  United States Court of Appeals
      for the Federal Circuit
                ______________________

        AKAMAI TECHNOLOGIES, INC.,
      THE MASSACHUSETTS INSTITUTE OF
               TECHNOLOGY,
              Plaintiffs-Appellants

                           v.

           LIMELIGHT NETWORKS, INC.,
              Defendant-Cross-Appellant
               ______________________

      2009-1372, 2009-1380, 2009-1416, 2009-1417
               ______________________

    Appeals from the United States District Court for the
District of Massachusetts in Nos. 06-CV-11585, 06-CV-
11109, Judge Rya W. Zobel.
                ______________________

                Decided: May 13, 2015
                ______________________

    SETH P. WAXMAN, Wilmer Cutler Pickering Hale and
Dorr LLP, Washington, DC, argued for plaintiffs-
appellants.  Also represented by THOMAS SAUNDERS,
THOMAS GREGORY SPRANKLING; MARK CHRISTOPHER
FLEMING, ERIC FLETCHER, LAUREN B. FLETCHER, BROOK
HOPKINS, Boston, MA; DAVID H. JUDSON, Law Offices of
David H. Judson, Dallas, TX; DONALD ROBERT DUNNER,
KARA F. STOLL, ELIZABETH D. FERRILL, Finnegan, Hender-
son, Farabow, Garrett & Dunner, LLP, Washington, DC;
JENNIFER S. SWAN, Palo Alto, CA; ROBERT S. FRANK, JR.,
2   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



G. MARK EDGARTON, CARLOS PEREZ-ALBUERNE, Choate,
Hall & Stewart, LLP, Boston, MA.

    AARON M. PANNER, Kellogg, Huber, Hansen, Todd,
Evans & Figel, P.L.L.C., Washington, DC, argued for
defendant-cross appellant. Also represented by JOHN
CHRISTOPHER     ROZENDAAL,    MICHAEL     E.    JOFFRE;
ALEXANDER FRASER MACKINNON, Kirkland & Ellis LLP,
Los Angeles, CA; YOUNG JIN PARK, New York, NY; DION
D. MESSER, Limelight Networks, Inc., Tempe, AZ.

    JERRY ROBIN SELINGER, Patterson & Sheridan LLP,
Dallas, TX, for amici curiae Altera Corporation, HTC
America, Inc., HTC Corporation, Weatherford Interna-
tional, Inc. Also represented by B. TODD PATTERSON,
Houston, TX; GERO MCCLELLAN, Greensboro, NC.

    WILLIAM G. BARBER, Pirkey Barber LLP, Austin, TX,
for amicus curiae American Intellectual Property Law
Association.

    TIMOTHY TETER, Cooley LLP, Palo Alto, CA, for ami-
cus curiae Apple Inc. Also represented by BENJAMIN G.
DAMSTEDT, IAIN R. CUNNINGHAM, LORI R. MASON; PATRICK
J. MURPHY, Apple Computer Inc., Cupertino, CA.

    MEREDITH MARTIN ADDY, Katten Muchin Rosenman
LLP, Chicago, IL, for amici curiae Aristocrat Technologies
Australia PTY Limited, Aristocrat Technologies, Inc. Also
represented by ANTHONY R. DE ALCUAZ, McDermott, Will
& Emery LLP, Menlo Park, CA.

    JOHN W. RYAN, Thompson Hine LLP, Washington,
DC, for amicus curiae Biotechnology Industry Organiza-
tion. Also represented by HANSJORG SAUER, Biotechnology
Industry Organization, Washington, DC; THOMAS M.
HAAS, Sullivan & Worcester, Washington, DC.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   3



    JEFFREY E. FRANCIS, Pierce Atwood LLP, Boston, MA,
for amicus curiae Boston Patent Law Association.

   GREGORY PAUL STONE, Munger, Tolles & Olson LLP,
Los Angeles, CA, for amicus curiae CTIA The Wireless
Association. Also represented by HEATHER E. TAKAHASHI,
ANDREW W. SONG.

    RAYMOND PARDO NIRO, I, Niro, Haller & Niro, Chica-
go, IL, for amici curiae Cascades Ventures, Inc., VNS
Corporation. Also represented by JOHN C. JANKA.

    EDWARD R. REINES, Weil, Gotshal & Manges LLP,
Redwood Shores, CA, for amici curiae Cisco Systems, Inc.,
Dell Inc., Google Inc., Hewlett-Packard Company, Intel
Corporation, Intuit Inc., Micron Technology, Inc., NetApp,
Inc., Ringcentral, Inc., SAP America, Inc., Symantec
Corporation, Yahoo! Inc., Zynga Inc., Ebay, Inc. Also
represented by NATHAN A. GREENBLATT.

   STEVEN C. SEREBOFF, SoCal IP Law Group LLP,
Westlake Village, CA, for amicus curiae Conejo Valley
Bar Association. Also represented by MEENAKSHI KALA
SARVAIYA, MARK ANDREW GOLDSTEIN.

   JULIE P. SAMUELS, Electronic Frontier Foundation,
San Francisco, CA, for amicus curiae Electronic Frontier
Foundation. Also represented by MICHAEL BARCLAY.

    MATTHEW D. MCGILL, Gibson, Dunn & Crutcher LLP,
for amici curiae Facebook, Inc., LinkedIn Corporation,
Also represented by WILLIAM G. JENKS, Jenks IP Law,
Washington, DC.

    JOHN STEVEN GARDNER, Kilpatrick Townsend &
Stockton LLP, Winston-Salem, NC, for amicus curiae The
Financial Services Roundtable. Also represented by
4   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



ALTON LUTHER ABSHER; GIA L. CINCONE, San Francisco,
CA.

   PETER J. BRANN, Brann & Isaacson, Lewiston, ME, for
amicus curiae Internet Retailers. Also represented by
STACY O. STITHAM, DAVID SWETNAM-BURLAND.

    GARRETH A. SAROSI, Winstead Attorneys, Dallas, TX,
for amicus curiae MetroPCS Wireless, Inc. Also repre-
sented by MARK ATKERSON STACHIW, Metro PCS Commu-
nications Inc., Richardson, TX.

    BENJAMIN JACKSON, Myriad Genetics, Salt Lake City,
UT, for amicus curiae Myriad Genetics, Inc. Also repre-
sented by JAY Z. ZHANG.

   CHARLES A. WEISS, Kenyon & Kenyon LLP, New York,
NY, for amicus curiae New York Intellectual Property
Law Association. Also represented by THERESA M. GILLIS,
Mayer Brown, LLP, New York, NY.

    ROBERT P. TAYLOR, Arnold & Porter, LLP, San Fran-
cisco, CA, for amicus curiae Pharmaceutical Research and
Manufacturers of America. Also represented by MONTY
AGARWAL; LISA A. ADELSON, DAVID R. MARSH, Washing-
ton, DC; DAVID EVAN KORN, Pharmaceutical Research and
Manufacturers Association of America, Washington, DC.

   VICKI GEE NORTON, Duane Morris LLP, San Diego,
CA, for amicus curiae The San Diego Intellectual Property
Law Association.

   ERIC LAURENCE ABBOTT, Abbott Law Chartered, Las
Vegas, NV, for amicus curiae Shuffle Master, Inc.

    CALVIN L. LITSEY, Faegre Baker Daniels LLP, Minne-
apolis, MN, for amicus curiae Thomson Reuters Corpora-
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   5



tion. Also represented by TIMOTHY M. SULLIVAN, AARON D.
VAN OORT, CHRISTOPHER J. BURRELL.

    MICHAEL K. KIRSCHNER, Hillis, Clark, Martin & Pe-
terson P.S., Seattle, WA, for amicus curiae Washingon
State Patent Law Association. Also represented by
ALEXANDER M. WU.

    CHARLES R. MACEDO, Amster Rothstein & Ebenstein
LLP, New York, NY, for amici curiae Double Rock Corpo-
ration, Island Intellectual Property, LLC, Broadband ITV,
Inc. Also represented by JESSICA A. CAPASSO.
                  ______________________

  Before PROST, Chief Judge, LINN, and MOORE, ∗ Circuit
                        Judges.
    Opinion for the court filed by Circuit Judge LINN.
    Dissenting opinion filed by Circuit Judge MOORE.
LINN, Circuit Judge.
    This appeal returns to us following remand from the
United States Supreme Court. See Limelight Networks,
Inc. v. Akamai Techs., Inc., 134 S. Ct. 2111 (2014). Be-
cause our prior decisions in BMC Resources, Inc. v. Pay-
mentech, L.P., 498 F.3d 1373 (Fed. Cir. 2007), and
Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318 (Fed.
Cir. 2008), directly apply to the facts of this case and
because the statutory framework of 35 U.S.C. § 271 does
not admit to the sweeping notions of common-law tort
liability argued in this case, we again conclude that


   ∗
        Pursuant to Fed. Cir. Internal Operating Proce-
dure 15 ¶ 2(b)(ii) (Nov. 14, 2008), Circuit Judge Moore
was designated to replace Randall R. Rader, now retired,
on this panel.
6   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



because Limelight Networks, Inc. (“Limelight”) did not
perform all of the steps of the asserted method claims of
U.S. Patent No. 6,108,703 (the “’703 patent”) and because
the record contains no basis on which to impose liability
on Limelight for the actions of its customers who carried
out the other steps, Limelight has not directly infringed
the ’703 patent under § 271(a). Accordingly, we affirm the
district court’s finding of noninfringement and do not
reach Limelight’s cross-appeal regarding damages. We
also confirm our previously reinstated affirmance of the
district court’s judgment of noninfringement of U.S.
Patents No. 6,553,413 (the “’413 patent”) and No.
7,103,645 (the “’645 patent”). See Akamai, 629 F.3d 1311
(Fed. Cir. 2010), which was vacated, 419 F. App’x 989
(Fed. Cir. 2011) (en banc), and then partially reinstated.
Order No. 2009-1372 (Fed. Cir. Sept. 27, 2012) (en banc).
                     I. BACKGROUND
    A detailed description of the history of proceedings,
the technology and the claims at issue in this case is set
forth in the prior reported opinions of this court and the
Supreme Court and will not be repeated except to the
extent germane hereto. See Limelight, 134 S. Ct. 2111;
Akamai, 692 F.3d 1301 (Fed. Cir. 2012) (en banc); Aka-
mai, 629 F.3d 1311.
       II. DIVIDED INFRINGEMENT UNDER § 271(a)
    In the court’s view, and for the reasons set forth in
more detail, infra, direct infringement liability of a meth-
od claim under 35 U.S.C. § 271(a) exists when all of the
steps of the claim are performed by or attributed to a
single entity—as would be the case, for example, in a
principal-agent relationship, in a contractual arrange-
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.    7



ment, or in a joint enterprise. 1 Because this case involves
neither agency nor contract nor joint enterprise, we find
that Limelight is not liable for direct infringement.
    Direct infringement under § 271(a) requires a party to
perform or use each and every step or element of a
claimed method. Warner-Jenkinson Co. v. Hilton Davis
Chem. Co., 520 U.S. 17, 29 (1997). For method patent
claims, direct infringement only occurs when a single
party or a joint enterprise performs all of the steps of the
process. See Joy Techs., Inc. v. Flakt, Inc., 6 F.3d 770, 775
(Fed. Cir. 1993) (“A method claim is directly infringed
only by one practicing the patented method.” (emphasis
omitted)); Fromson v. Advance Offset Plate, Inc., 720 F.2d
1565, 1567–68 (Fed. Cir. 1983) (“Because the [method]
claims include the application of a diazo coating or other
light sensitive layer and because Advance’s customers,
not Advance, applied the diazo coating, Advance cannot
be liable for direct infringement with respect to those
plates.”). This holding derives from the statute itself,
which states “whoever without authority makes, uses,
offers to sell, or sells any patented invention, within the
United States or imports into the United States any
patented invention during the term of the patent therefor,
infringes the patent.” § 271(a). Encouraging or instruct-
ing others to perform an act is not the same as performing
the act oneself and does not result in direct infringement.
BMC, 498 F.3d at 1378–79. This is evidenced by the fact
that § 271 has separate subsections addressing induced
and contributory infringement. When a party partici-
pates in or encourages infringement but does not directly
infringe a patent, the normal recourse under the law is for



    1   Because this case does not implicate joint enter-
prise liability, this case is not the appropriate vehicle to
adopt joint enterprise liability.
8    AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



the court to apply the standards for liability under indi-
rect infringement. Id. However, indirect infringement
requires, as a predicate, a finding that some party is
directly liable for the entire act of direct infringement.
Limelight, 134 S. Ct. at 2115. In circumstances in which
one party, acting as “mastermind” exercises sufficient
“direction or control” over the actions of another, such
that those actions may be attributed to the mastermind,
the combined performance of the steps of a method claim
will directly infringe under § 271(a). BMC, 498 F.3d at
1382. “Under BMC Resources, the control or direction
standard is satisfied in situations where the law would
traditionally hold the accused direct infringer vicariously
liable for the acts committed by another party that are
required to complete performance of a claimed method.”
Muniauction, 532 F.3d at 1330. This may occur in a
principal-agent relationship, a contractual relationship or
in circumstances in which parties work together in a joint
enterprise functioning as a form of mutual agency.
     Akamai asserts that the Supreme Court’s Limelight
decision “strongly implies that a change in direction on
§ 271(a) is warranted.” Br. for Akamai at 3, Akamai, No.
2009-1372 (Fed. Cir. Aug. 18, 2014) (“Akamai’s Letter
Br.”). It claims that in lieu of overruling Muniauction,
this panel can decline to extend it to the facts of this case.
Id. According to Akamai, an accused infringer “directs or
controls” a third party if the accused infringer goes be-
yond loosely providing instructions and specifically tells a
third party the step or steps to perform. Id. at 9. In its en
banc briefing, Akamai cites joint tortfeasor principles as
support. See, e.g., Principal Br. for Pls.-Appellants at 21,
Akamai, 692 F.3d 1301 (available at 2011 WL 2822716)
(citing Restatement (Second) of Agency § 212, cmt. a
(discussing the tort principle that “one causing and in-
tending an act or result is as responsible as if he had
personally performed the act or produced the result”)); id.
at 22 (quoting Restatement (Second) of Torts § 877(a)
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.     9



(subjecting a party to liability for “order[ing]” conduct)).
Limelight responds that Akamai’s expansive attribution
theory “would render both Section 271(b) and Section
271(c) meaningless.” Br. of Def.-Cross-Appellant Lime-
light Networks, Inc. on Rehearing En Banc at 41, Akamai,
692 F.3d 1301 (available at 2011 WL 3796785) (quoting
Mark A. Lemley et al., Divided Infringement Claims, 6
Sedona Conf. J. 117, 119–20 (2005) (“Lemley”)).
    We begin by considering whether § 271(a) incorpo-
rates joint tortfeasor liability, as Akamai and the dissent
advocate. Unquestionably, it does not. As codified by
Congress, § 271(a) includes only the principles of vicarious
liability, as embodied in the single entity rule. Presented
with numerous conflicting theories of joint liability that
existed in the common law prior to 1952, Congress enact-
ed specific rules for inducement and contributory liability
in § 271(b) and (c), respectively. While the dissent be-
lieves this leaves a “gaping hole,” Dissent at 1, it is not
our position to legislate or contravene Congress’ choice—
right or wrong—by importing other theories of joint
liability into § 271(a).
     The alternative—stretching § 271(a) to include joint
tortfeasor liability—is flawed. To make joint tortfeasor
liability consistent with the well-established fact that
direct infringement liability under § 271(a) is strict liabil-
ity, Akamai and the dissent must abandon several core
tenets of joint tortfeasor law. This position also leads to
untenable results. For example, the dissent advocates
holding a customer jointly and severally liable for patent
infringement based on its performance of a single step of
a claimed method, even when it has no knowledge of the
patent.
    In the analysis that follows we address, in turn, three
subjects: the statutory scheme of § 271, the divided in-
fringement case law, and the errors in importing joint
tortfeasor liability into § 271(a).
10   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



     A. The Statutory Scheme of § 271
     Patent infringement is not a creation of common law.
It is a tort defined by statute. See Crown Die & Tool Co.
v. Nye Tool & Mach. Works, 261 U.S. 24, 40 (1923) (“The
monopoly [granted to the patentee] did not exist at com-
mon law, and the rights, therefore, which may be exer-
cised under it cannot be regulated by the rules of the
common law.” (quoting Gayler v. Wilder, 51 U.S. (10
How.) 477, 494 (1850))); 3D Sys., Inc. v. Aarotech Labs.,
Inc., 160 F.3d 1373, 1379 (Fed. Cir. 1998) (“Defining the
contours of the tort of infringement, which exists solely by
virtue of federal statute, entails the construction of the
federal statute and not a state’s common or statutory
law.” (citing N. Am. Philips Corp. v. Am. Vending Sales,
Inc., 35 F.3d 1576, 1579 (Fed. Cir. 1994)).
     35 U.S.C. § 271(a) provides that:
     Except as otherwise provided in this title, whoev-
     er without authority makes, uses, offers to sell, or
     sells any patented invention, within the United
     States or imports into the United States any pa-
     tented invention during the term of the patent
     therefor, infringes the patent.
Section 271(a) defines infringement. H.R. Rep. No. 82-
1923, at 9 (1952) (“Section 271, paragraph (a), is a decla-
ration of what constitutes infringement.” (emphasis add-
ed)). Subsections (b) and (c), in turn, codify the doctrines
of inducement and contributory infringement respectively.
     The Supreme Court has observed that “the 1952 Act
did include significant substantive changes, and . . . § 271
was one of them.” Dawson Chem. Co. v. Rohm & Haas
Co., 448 U.S. 176, 204 (1980). In the 1952 Patent Act,
Congress removed joint-actor patent infringement liabil-
ity from the discretion of the courts, defining “infringe-
ment” in § 271(a) and expressly outlining in § 271(b) and
(c) the only situations in which a party could be liable for
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   11



something less than an infringement. This was purpose-
ful. At the time, the courts applied a myriad of approach-
es to multi-actor infringement: some liberally allowed for
multi-actor liability, see, e.g., Peerless Equip. Co. v. W.H.
Miner, Inc., 93 F.2d 98, 105 (7th Cir. 1937); Solva Water-
proof Glue Co. v. Perkins Glue Co., 251 F. 64, 73–74 (7th
Cir. 1918), while others nearly never permitted multi-
actor liability, see, e.g., Mercoid Corp. v. Mid-Continent
Inv. Co., 320 U.S. 661, 669 (1944) (“[w]hat residuum [of
contributory infringement] may be left we need not stop to
consider”); Mercoid Corp. v. Minneapolis-Honeywell
Regulator Co., 320 U.S. 680, 684 (1944). In enacting
§ 271(b) and (c), Congress cleared away the morass of
multi-actor infringement theories that were the unpre-
dictable creature of common law in favor of two infringe-
ment theories that it defined by statute. See Contributory
Infringement in Patents—Definition of Invention: Hear-
ings on H.R. 5988, 4061, and 5248 Before the Subcomm.
on Patents, Trademarks, and Copyrights of the H. Comm.
on the Judiciary, 80th Cong. 12 (1948) (statement of Giles
S. Rich on behalf of the New York Patent Law Ass’n)
(“contributory infringement is a specific application to
patent law of the law of joint tort feasor”); Hearing on
H.R. 3866 Before Subcomm. No. 4 of the H. Comm. on the
Judiciary, 81st Cong. 2 (1949) (statement of Giles S. Rich
on behalf of the New York Patent Law Ass’n) (“Time out
of mind, under the old common law, there has been a
doctrine of joint tort feasors to the effect that people who
jointly commit a tort are jointly and severally liable. This
contributory infringement is nothing but the application
of that doctrine to patent law.”); id. at 3, 6–7; Giles S.
Rich, Infringement Under Section 271 of the Patent Act of
1952, 35 J. Pat. Off. Soc’y 476, 480 (1953) (“Contributory
infringement is an expression of the old common law
doctrine of joint tort feasors.” (emphases in original)).
    Indeed, in this way, Congress carefully crafted sub-
sections (b) and (c) to expressly define the only ways in
12       AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



which individuals not completing an infringing act under
§ 271(a) could nevertheless be liable. See, e.g., Dawson,
448 U.S. at 187–214 (discussing at length the state of
contributory infringement prior to the 1952 Patent Act
and the legislative history of the 1952 Act). Therefore, to
the extent that tort law’s contributory liability principles
are applicable at all, § 271(b) and (c) embody the applica-
tion of contributory liability principles to patent law. See
Cent. Bank of Denver, N.A. v. First Interstate Bank of
Denver, N.A., 511 U.S. 164, 184 (1994) (“The fact that
Congress chose to impose some forms of secondary liabil-
ity, but not others, indicates a deliberate congressional
choice with which the courts should not interfere.”). We
must respect Congress’ deliberate choice to enact only
certain forms of contributory liability in § 271(b) and (c). 2



     2  Akamai and the dissent argue that the word
“whoever” in § 271(a) (“whoever . . . uses . . . any patented
invention”) undermines the single entity rule because it is
plural. See 1 U.S.C. § 1 (“In determining the meaning of
any Act of Congress, unless the context indicates other-
wise—words importing the singular include and apply to
several persons, parties, or things . . . .” (emphasis add-
ed)). The court agrees that “whoever” is plural, but Aka-
mai and the dissent’s argument fails for two reasons.
First, the statute simply states the obvious: more than
one entity can be independently liable for direct patent
infringement if each entity practices every element of the
claim. Second, the statutory context, with § 271(b) and (c)
extending liability in limited circumstances to actors who
do not independently infringe, establishes that § 271(a)
excludes joint liability.
    The dissent’s interpretation of “whoever” as “any per-
son or persons” is also too sweeping for its purposes. The
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   13



     Furthermore, Akamai’s broad theory of attribution—
in which a defendant would be liable for “causing and
intending an act or result,” Akamai’s Letter Br. at 4
(citations omitted)—would render § 271(b) redundant.
Subsection (b) states: “Whoever actively induces in-
fringement of a patent shall be liable as an infringer.”
The Supreme Court in Global-Tech, quoting Webster’s,
explained that to induce “means to lead on; to influence;
to prevail on; to move by persuasion or influence.” Global-
Tech Appliances, Inc. v. SEB S.A., 131 S. Ct. 2060, 2065
(2011) (quoting Webster’s New International Dictionary
1269 (2d ed. 1945)) (internal citations and brackets omit-
ted). Webster’s contains several, somewhat overlapping,
definitions for “induce,” one of which is “cause.” Webster’s
at 1269; accord Dansereau v. Ulmer, 903 P.2d 555, 564
(Alaska 1995); United States v. McQueen, 670 F.3d 1168,
1170 (11th Cir. 2012). And even the definitions expressly
quoted in Global-Tech—namely: to lead on; to influence;
to prevail on; to move by persuasion or influence—are all
ways to “cause.” The Supreme Court in Global-Tech
further explained that the adverb “actively” means that
“the inducement must involve the taking of affirmative
steps to bring about the desired result.” 131 S. Ct. at
2065 (citing Webster’s at 27). This “obviously [requires]



plain meaning of § 271(a), as the dissent would have it,
contains no requirement that the parties “act in concert
pursuant to a common plan or design,” Dissent at 21, and
the dissent introduces it with no statutory basis. The
dissent’s analogy to joint inventors, see id. at 10, 15, 16,
only underscores this problem. That joint inventors must
have some connection derives from the word “jointly”
found in § 116—see, e.g., Bard Peripheral Vascular, Inc. v.
W.L. Gore & Assocs., Inc., 776 F.3d 837, 846 (Fed. Cir.
2015) (citing cases)—not from the word “[w]hoever.”
14   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



know[ing] the action that [the inducer] wishes to bring
about.” Id. Thus, a defendant actively induces patent
infringement under § 271(b) if she causes infringement
while intending the act or result to occur (along with
certain other requirements). See Black’s Law Dictionary
1321 (8th ed. 1999) (defining “active inducement” as “[t]he
act of intentionally causing a third party to infringe a
valid patent”).
    But if, as Akamai contends, there is liability under
§ 271(a) for “one causing and intending an act or result,”
there is no need for a separate tort for induced infringe-
ment. This is crystallized by the language of the Re-
statement (Second) of Torts § 877(a)—cited by Akamai—
which subjects a defendant to liability for tortious conduct
of another if the defendant “orders or induces the conduct”
(emphasis added).
    For essentially the same reasons, Akamai’s broad
reading of § 271(a) would make § 271(c) redundant as
well. Subsection (c), as originally enacted, stated:
     (c) Whoever sells a component of a patented ma-
     chine, manufacture, combination or composition,
     or a material or apparatus for use in practicing a
     patented process, constituting a material part of
     the invention, knowing the same to be especially
     made or especially adapted for use in an in-
     fringement of such patent, and not a staple article
     or commodity of commerce suitable for substantial
     noninfringing use, shall be liable as a contributory
     infringer.
As with § 271(b), liability for § 271(c) requires knowledge
or willful blindness of the patent, Global-Tech, 131 S. Ct.
at 2068, and requires direct infringement. Aro Mfg. Co. v.
Convertible Top Replacement Co. (Aro II), 377 U.S. 476,
484 (1964). Thus, § 271(c) also entails causing customers
to act as they did and intending the acts and/or results.
There is no principled reason why Akamai’s attribution
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   15



theory should not apply to combination patents. But it is
well settled that the sale of an unpatented component will
at most raise a question of infringement under subsection
(c), not subsection (a). See 35 U.S.C. § 271(c); Aro Mfg.
Co. v. Convertible Top Replacement Co. (Aro I), 365 U.S.
336, 339–40 (1961) (because “the fabric is no more than
an unpatented element of the combination which was
claimed as the invention[,] [i]t follows that petitioners’
manufacture and sale of the fabric is not a direct in-
fringement under 35 U.S.C. § 271(a)”).
     While Akamai at various points uses slightly different
phrasing for when one party’s actions should be attribut-
ed to another, all of its proposed tests suffer the same
failing: they make § 271(b) and (c) redundant. Akamai’s
proposed interpretation thus contravenes the rule that
“we construe statutes, where possible, so as to avoid
rendering superfluous any parts thereof.” Astoria Fed.
Sav. & Loan Ass’n v. Solimino, 501 U.S. 104, 111 (1991).
    The dissent is faced with the same problem. To man-
ufacture a single case in which its expansive interpreta-
tion of § 271(a) would not render § 271(b) and (c)
superfluous, the dissent imposes a requirement that each
joint patent infringer must perform at least one step of
the method, see Dissent at 14. However, this single step
requirement necessitates a new and untested definition of
the word “uses.” It also conflicts with the common law of
torts—the authority cited by the dissent for its broad
interpretation of § 271(a). The common law of torts would
hold liable an entity that, with sufficient intent, aided
another in committing a tort, even if that entity did not
commit any element of the tort itself.
   B. Divided Infringement Case Law
    Under the language of § 271(a), this court’s “divided
infringement” case law is rooted in traditional principles
of vicarious liability. Under the principles of vicarious
liability, direct infringement does not occur unless all
16   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



steps of a method claim are performed by or attributable
to a single entity. This is the single entity rule. BMC
confirmed that where the actions of one party can be
legally imputed to another, such that a single entity can
be said to have performed each and every element of the
claim, that single entity is liable as a direct infringer. 498
F.3d at 1380–81. Before BMC, the judiciary and the
patent law community recognized that multiple actors
could together infringe a patent only if one controlled the
other(s). See Mobil Oil Corp. v. Filtrol Corp., 501 F.2d
282, 291–92 (9th Cir. 1974) (“Mobil contends that Filtrol
and Texaco split between them the performance of the
four steps of the claim . . . . We question whether a meth-
od claim can be infringed when two separate entities
perform different operations and neither has control of the
other’s activities. No case in point has been cited.” (em-
phasis added)); BMC Res., Inc. v. Paymentech, L.P., No.
3:03-cv-1927, 2006 WL 1450480, at *4 (N.D. Tex. May 24,
2006); Lemley, 6 Sedona Conf. J. at 118 (“[C]ourts have
imposed liability for direct infringement where another
person acts as an agent of the alleged infringer.” (empha-
sis added)).
     Applying traditional principles of vicarious liability to
direct infringement under § 271(a) protects patentees
from a situation where a party attempts to “avoid in-
fringement . . . simply by contracting out steps of a pa-
tented process to another entity . . . . It would be unfair
indeed for the mastermind in such situations to escape
liability.” BMC, 498 F.3d at 1381. In addition, in patent
law, unlike in other areas of tort law—where the victim
has no ability to define the injurious conduct upfront—the
patentee specifically defines the boundaries of his or her
exclusive rights in the claims appended to the patent and
provides notice thereby to the public so that it can avoid
infringement. As this court correctly recognized in BMC,
“[t]he concerns over a party avoiding infringement by
arms-length cooperation can usually be offset by proper
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   17



claim drafting. A patentee can usually structure a claim
to capture infringement by a single party.” 498 F.3d at
1381. Further, many amici have pointed out that the
claim drafter is the least cost avoider of the problem of
unenforceable patents due to joint infringement. It would
thus be unwise to overrule decades of precedent in an
attempt to enforce poorly-drafted patents.
    The dissent asserts that a handful of pre-1952 cases
conflict with the single entity rule. But all of these cases
do not involve method claims, see York & Md. Line R.R.
Co. v. Winans, 58 U.S. (17 How.) 30 (1854); Thomson-
Houston Elec. Co. v. Ohio Brass Co., 80 F. 712 (6th Cir.
1897); Wallace v. Holmes, 29 F. Cas. 74, 80 (C.C.D. Conn.
1871); Jackson v. Nagle, 47 F. 703, 703 (C.C.N.D. Cal.
1891); N.J. Patent Co. v. Schaeffer, 159 F. 171, 173
(C.C.E.D. Pa. 1908) 3), and/or concern contributory (as
opposed to direct) infringement. See Peerless, 93 F.2d at
105; Solva, 251 F. at 73; Thomson-Houston, 80 F. at 721;
Wallace, 29 F. Cas. 74. 4 Cases discussing apparatus (as
opposed to method) claims are not helpful because whoev-
er combines the last element of an apparatus necessarily,



   3    Jackson related to a claim for infringement of
claims 1, 4, and 5 of U.S. Patent No. 263,412 (the “’412
patent”), claims 1 and 2 of U.S. Patent No. 269,863 (the
“’863 patent”), and claims 2 and 3 of U.S. Patent No.
302,338 (the “’338 patent”). 47 F. at 703. Schaeffer
related to a claim for infringement of U.S. Patent No.
782,375 (the “’375 patent”). 159 F. at 172. None of these
are method claims. See ’412, ’863, ’338 and ’375 patents.
     4  Though Wallace does not explicitly use the term,
it is a recognized example of contributory infringement.
See Dawson, 448 U.S. at 187–88; Aro II, 377 U.S. at 500;
Henry v. A.B. Dick Co., 224 U.S. 1, 34 (1912) (all describ-
ing Wallace as an example of contributory infringement).
18   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



individually, “makes” the invention. Thus, in the case of
an apparatus claim, there is always a single entity direct-
ly infringing the patent. By contrast, because “a process
is nothing more than the sequence of actions of which it is
comprised, the use of a process necessarily involves doing
or performing each of the steps recited.” NTP, Inc. v.
Research in Motion, Ltd., 418 F.3d 1282, 1318 (Fed. Cir.
2005). As such, only method claims can raise an issue of
divided infringement.
    The contributory infringement cases are, by their
terms, not discussing direct infringement. The dissent
acknowledges this, see Dissent at 20 (“some of the[se] pre-
1952 principles and cases . . . are more akin to what we
today consider to be indirect infringement than direct
infringement under § 271(a)”), but suggests that the 1952
Act changed the contours of direct infringement, catego-
rizing certain behaviors that formerly were described as
contributory infringement as direct infringement. This is
wrong. The enactment of § 271(a) “left intact the entire
body of case law on direct infringement.”          Warner-
Jenkinson, 520 U.S. at 26–27 (quoting Aro I, 365 U.S. at
342). Today, just as in 1952, where a single entity does
not perform each and every claim limitation, that entity
may not be characterized or held liable as a direct infring-
er. See Aro I, 365 U.S. at 340; Fromson, 720 F.2d at
1567–68. Contributory actions—such as the performance
of some, but not all, steps of a method claim—do not meet
the all elements test, and thus must be analyzed exclu-
sively under the rules of indirect infringement. BMC, 498
F.3d at 1381 (“[E]xpanding the rules governing direct
infringement to reach independent conduct of multiple
actors would subvert the statutory scheme for indirect
infringement.”). Therefore, the principles of vicarious
liability govern § 271(a).
    Turning to the scope of vicarious liability, the vicari-
ous liability test includes, for example, principal-agent
relationships, contractual arrangements, and joint enter-
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.    19



prises. In a principal-agent relationship, the actions of
the agent are attributed to the principal. Similarly, when
a contract mandates the performance of all steps of a
claimed method, each party to the contract is responsible
for the method steps for which it bargained. However,
this type of contractual arrangement will typically not be
present in an arms-length seller-customer relationship.
   Finally, in a joint enterprise, the acts of each partici-
pant are, by definition, imputed to every member.
   All members of a joint venture may be jointly and
   severally liable to third persons for wrongful acts
   committed in furtherance of the joint enterprise or
   venture. Thus, the negligence of one participant
   in the enterprise or venture, while acting within
   the scope of agency created by the enterprise, may
   be imputed to another participant so as to render
   the latter liable for the injuries sustained by third
   persons as a result of the negligence.
48A C.J.S. Joint Ventures § 62 (footnotes omitted); see
also Restatement (Second) of Torts § 491 (1965) (“Any one
of several persons engaged in a joint enterprise, such as to
make each member of the group responsible for physical
harm to other persons caused by the negligence of any
member, is barred from recovery against such other
persons by the negligence of any member of the group.”).
A joint enterprise exists for the purposes of imposing
vicarious liability when there is:
   (1) an agreement, express or implied, among the
   members of the group; (2) a common purpose to be
   carried out by the group; (3) a community of pecu-
   niary interest in that purpose, among the mem-
   bers; and (4) an equal right to a voice in the
   direction of the enterprise, which gives an equal
   right of control.
20   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



Restatement (Second) of Torts § 491, cmt. c.; see also 57B
Am. Jur. 2d Negligence § 1138 (2015).
     C. Errors in Importing Joint Tortfeasor Liability into
        § 271(a)
    The majority and dissent agree that liability exists
under traditional principles of vicarious liability, such as
where a mastermind directs or controls another to per-
form all steps of a claimed method. But the dissent’s rule
is far broader—Akamai and the dissent insist that they
can thrust common law joint tortfeasor liability into
§ 271(a). The dissent would extend liability to “include[]
parties who act in concert to collectively perform the
claimed process pursuant to a common plan, design, or
purpose.” Dissent at 16. The error of this approach is
that it attempts to fit a square peg in a round hole: joint
tortfeasor law and § 271 are fundamentally incompatible.
To import joint tortfeasor law into § 271(a), Akamai and
the dissent depart from three indispensable common law
limits on joint tortfeasor liability.
    First, the Restatement is clear that joint tortfeasor li-
ability “includes only situations in which the defendant
has been personally guilty of tortious conduct.” Restate-
ment (Second) of Torts § 875, cmt. a (1979). Yet personal
guilt of direct infringement of a method claim under
§ 271(a) requires performance by the accused of all steps
recited in the claim. The Restatement (Second) of Torts
§ 876, cmt. c (1979) explains that “[o]ne who innocently,
rightfully and carefully does an act that has the effect of
furthering the tortious conduct or cooperating in the
tortious design of another is not for that reason subject to
liability.” Thus, contrary to Akamai’s and the dissent’s
positions, actors whose innocent actions coordinate to
cause harm generally are not subject to liability at com-
mon law.
   Second, the dissent purports to adopt the Restate-
ment’s rule of action in concert. But, according to the
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.    21



Restatement, “[p]arties are acting in concert when they
act in accordance with an agreement to cooperate in a
particular line of conduct or to accomplish a particular
result.” Restatement (Second) of Torts § 876, cmt. a. This
definition stresses that there must be mutual agreement
between the parties. Thus, the Restatement describes
“acting in concert” as a form of “mutual agency.” Id. This
is consistent with the early patent law treatises that
limited joint infringement to parties “acting in complicity
with others,” 3 William C. Robinson, The Law of Patents
for Useful Inventions § 946 (1890), or parties “coop-
erat[ing]” in infringement, Albert H. Walker, Textbook of
the Patent Laws of the United States of America § 406 (4th
ed. 1904). There is no mutual agency or cooperation when
parties act independently for their own benefit, such as in
arms-length seller-customer relationships.
     The dissent, meanwhile, would extend liability even
to arms-length agreements, so long as one party “know[s]
of th[e] [other] party’s actions.” Dissent at 27. This
position contravenes both patent law and tort law. The
Supreme Court in Global-Tech held that “a direct infring-
er’s knowledge or intent is irrelevant,” 131 S. Ct. at 2065
n.2, yet the dissent imposes a knowledge require-
ment. And common tort law requires both parties to
know the others’ actions to act in concert. See Restate-
ment (Second) of Torts § 876(a) (“a tortious act in concert
with the other or pursuant to a common design with him”
(emphases added)). One party is “not acting in concert
with the other” if it “innocently, and carefully, does an act
which happens to further the tortious purpose of [the]
[]other.” W. Page Keeton et al., Prosser & Keeton on Torts
§ 46 (1984). Further, as Prosser and Keeton make clear,
even more is required. “There are even occasional state-
ments that mere knowledge by each party of what the
other is doing is sufficient ‘concert’ to make each liable for
the acts of the other; but this seems clearly wrong.” Id.
(emphasis added). Here, there is no evidence that Lime-
22   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



light’s customers knew what steps Limelight was taking,
much less evidence that they coordinated further. Thus,
there was no concert of action. Contrast Dissent at 25
(stating that Limelight and its customers acted “in con-
cert”); id. at 29 (same).
    Third, the Restatement describes yet another re-
quirement for concerted action: knowledge of harm. The
common law sources cited in Akamai’s briefs acknowledge
that, for joint liability, a defendant needs knowledge of
damage done or harm caused. See Akamai’s Letter Br. at
5 (quoting Prosser, § 47, which requires knowing that the
conduct will “cause damage”); Br. for Resp’ts at 26, Aka-
mai, 134 S. Ct. 2111 (available at 2014 WL 1260422)
(“Akamai’s Supreme Court Br.”) (quoting Warren v.
Parkhurst, 92 N.Y.S. 725, 727 (N.Y. Sup. Ct. 1904), which
requires “knowing that the contributions by himself and
the others . . . w[ould] result necessarily in the destruction
of the plaintiff’s property” (emphasis and alterations in
Akamai’s Supreme Court Br.)); id. at 27 (quoting Folsom
v. Apple River Log-Driving Co., 41 Wis. 602, 610 (1877),
which found liability for flooding where defendant “had
notice beforehand of such obstruction, and of the fact that
its effect, together with the company’s use of the water
beyond its natural flow, would be to flo[od] the plaintiff’s
land” (alterations in Akamai’s Supreme Court Br.)); id. at
28–29 (quoting Wallace, 29 F. Cas. at 80, which imposed
joint liability where parties “engaged in a common pur-
pose to infringe the patent”). Indeed, this common law
requirement was statutorily enacted into 35 U.S.C.
§ 271(b) and (c). See Global-Tech, 131 S. Ct. at 2068
(holding that both subsections (b) and (c) “require[]
knowledge [or willful blindness] of the existence of the
patent that is infringed”).
    This is consistent with the description in Prosser &
Keeton requiring “a common plan or design to commit a
tortious act,” Prosser & Keeton on Torts § 46. To apply a
“knowledge of the harm” principle to § 271(a), however,
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   23



would require knowledge of the patent, knowledge of the
steps recited in the claims, and knowledge of the risk of
infringement presented by performance of those steps.
Adopting such a requirement for liability under § 271(a)
would be contrary to centuries of settled Supreme Court
precedent that “a direct infringer’s knowledge or intent is
irrelevant.” Global-Tech, 131 S. Ct. at 2065 n.2; see also
Hogg v. Emerson, 52 U.S. 587, 607 (1850).
    The dissent’s reasoning for eliminating these three
common law limits on joint tortfeasor liability is that “not
all joint tortfeasor scenarios are permissible under the
language of § 271(a).” Dissent at 28. But this simple
response is wholly insufficient—it does not explain why
patent law should allow for more expansive joint tortfea-
sor liability than other areas of law. The common law has
carefully crafted these limits on tort liability over centu-
ries, in light of fairness and justice. We may not blithely
toss these limits aside.
     The dissent’s rule also leads to several extraordinary
results. For example, a customer who performs a single
step of a patented method by merely using a product as
intended would be jointly and severally liable for direct
infringement under § 271(a). See Dissent at 10 (“‘whoev-
er . . . uses’ a process for the purposes of infringement
covers multiple parties who act in concert”). It is nothing
short of remarkable that while Congress and state legisla-
tors express their concern about the vulnerability of
innocent customers to charges of patent infringement,
Akamai and the dissent labor to create an unprecedented
interpretation of existing law to make customers signifi-
cantly more vulnerable to such charges. This is especially
troubling given that the customer can be liable even
without knowing of the patent. Moreover, the dissent’s
“knowledge of the others’ actions” requirement is an
illusory protection for customers and other unsuspecting
parties. Institution of a patent infringement lawsuit
informs accused infringers of third parties’ actions, so, at
24       AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



most, requiring knowledge of the others’ actions limits the
patentee’s recovery to post-suit damages.
     The drastic expansion of predatory customer suits is
not a theoretical concern. Several amici, the White
House, and other commentators identify numerous in-
stances where patentees have sent demand letters to or
sued dozens, hundreds, or, in some cases, even thousands
of unsophisticated downstream users. 5 If the law were
expanded to impose joint and several liability on users of
a single prior art method step, it would subject swathes of
innocent actors across diverse industries to these practic-
es. 6 Using real patents as examples, amici warn that
individuals could be liable for patent infringement for so
little as initiating communication with a doctor or swiping



     5  Br. of Amicus Curiae Elec. Frontier Found. in
Supp. of Def. at 6–8, Akamai, 692 F.3d 1301 (Fed. Cir.
Aug. 9, 2011) (available at 2011 WL 3796789) (“EFF Br.”);
Corrected Br. of Amici Curiae Cisco Sys., Inc. et al. in
Supp. of Def.-Cross-Appellant at 4–5, Akamai, 692 F.3d
1301 (Fed. Cir. Aug. 15, 2011) (available at 2011 WL
4438649) (“Cisco Br.”); Executive Office of the Presi-
dent, Patent Assertion and U.S. Innovation, at 10–12
(June 2013); Gaia Bernstein, The Rise of the End User in
Patent Litigation, 55 B.C. L. Rev. 1443, 1443–46 (2014);
Brian Love & James Yoon, Expanding Patent Law’s
Customer Suit Exception, 93 B.U. L. Rev. 1605, 1610–11
(2013).
    6   See, e.g., Br. of Amici Curiae Newegg and L.L.
Bean in Supp. of Pet’r at 18–22, Limelight, 134 S. Ct.
2111 (Feb. 28, 2014) (available at 2014 WL 880929); Br. of
Amici Curiae Cargill, Inc. et al. in Supp. of Pet’r Lime-
light Networks, Inc. at 8–10, Limelight, 134 S. Ct. 2111
(Mar. 3, 2014) (available at 2014 WL 880935); Cisco Br. at
4–7.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   25



a debit card. 7 Another amici explains that “the hundreds
if not thousands of contracts in a technology company’s
supply chain could expose each actor in that supply chain
to potential patent infringement liability . . . .” Cisco Br.
at 5. Based on this fact, a patentee could draft “depend-
ent claims whose sole purpose is to add prior art steps
precisely to increase the patent applicant’s litigation and
licensing options post-issuance.” Id. at 4.
    Finally, the dissent’s position leads to another per-
verse result: the addition of a claim limitation can actual-
ly serve to make more parties liable for infringement.
Consider a hypothetical in which independent claim 1
recites a “replicating” step and claim 2, dependent there-
from, adds the limitation of a “tagging” step. The dis-
sent’s rule, which requires only concerted action and does
not require attribution of the acts of one party to the
other, would result in a party that performs the tagging
step but not the replicating step being liable for directly
infringing dependent claim 2 while not being liable for
infringing the broader claim from which it depends. This
conflicts with the “long . . . established” rule that a de-
pendent claim cannot be infringed unless the independent
claim from which it depends is also infringed. Teledyne
McCormick Selph v. United States, 558 F.2d 1000, 1004
(Ct. Cl. 1977); accord Ferring B.V. v. Watson Labs., Inc.-
Fla., 764 F.3d 1401, 1411 (Fed. Cir. 2014) (“Because we
hold that the asserted independent claims of Ferring’s
patents are not infringed, the asserted dependent claims
are likewise not infringed.” (citing cases)).




    7  EFF Br. at 5; Br. of Amicus Curiae The Financial
Services Roundtable in Supp. of Limelight Networks, Inc.
and Affirmance at 27, Akamai, 692 F.3d 1301 (Fed. Cir.
Aug. 15, 2011) (available at 2011 WL 7730148).
26   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



               III. THE FACTS OF THIS CASE
    Akamai argues that the facts here are different from
those in Muniauction, because Limelight provides more
specific instructions and because it has a contract with its
customers. Akamai’s Letter Br. at 8–9; see also Corrected
Br. of Pls.-Appellants at 44, Akamai, 629 F.3d 1311
(available at 2009 WL 6849543) (“Akamai’s Op. Br.”).
Limelight argues that the law has not changed since the
original panel decision. The same precedents that led to
the original panel decision, most notably BMC and Mu-
niauction, are still binding on this court. Br. for Lime-
light at 1–2, Akamai, No. 2009-1372 (Fed. Cir. Aug. 18,
2014). In its original panel briefing, it argued that the
district court was correct that this case is “indistinguisha-
ble” from Muniauction. See Principal and Resp. Br. of
Def.-Cross-Appellant Limelight Networks, Inc. at 34,
Akamai, 629 F.3d 1311 (available at 2009 WL 5070030).
It further argues that even if there is a contract between
Limelight and its customers, which it contests, this con-
tract “does not compel the customer to do anything.” Id.
at 41.
    In this case, there is nothing to indicate that Lime-
light’s customers are performing any of the claimed
method steps as agents for Limelight, or in any other way
vicariously on behalf of Limelight. To the contrary,
Limelight’s customers direct and control their own use of
Limelight’s content delivery network (“CDN”). Lime-
light’s customers serve their own web pages, and decide
what content, if any, they would like delivered by Lime-
light’s CDN. Customers sometimes even have Limelight’s
CDN and competing CDNs simultaneously deliver the
same content. As such, customers—not Limelight—direct
and control which CDN delivers each and every object of
their content. Limelight’s customers do not become
Limelight’s agents simply because Limelight provides its
customers a written manual explaining how to operate
Limelight’s product.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   27



    Moreover, Limelight’s CDN is a service similar to
Thomson’s on-line auction system in Muniauction, and
Limelight’s relationship with its customers is similar to
Thomson’s relationship with the bidders. In both cases,
customers are provided instructions on use of the service
and are required to perform some steps of the claimed
method to take advantage of that service. In Muniauc-
tion, the customers performed the step of bidding. Here,
the customers determine what website content should be
delivered by Limelight’s CDN and then, allegedly, per-
form the step of “tagging” that content. Limelight’s
customers also perform the step of “serving” their own
web pages. As the district court found, there is “no mate-
rial difference between Limelight’s interaction with its
customers and that of Thompson in Muniauction.” Aka-
mai, 614 F. Supp. 2d at 122.
    Akamai also argues that the relationship between
Limelight and its customers compels a finding of in-
fringement because Limelight “contracts out to content
providers the claim steps that it alone does not perform.”
Akamai’s Op. Br. at 40. This assertion stems from Lime-
light’s standard form contract that, according to Akamai,
“obligates content providers to perform the claim steps of
tagging the embedded objects and serving the tagged page
so that requests for the embedded objects resolve to
Limelight’s network instead of the content provider’s.” Id.
For this argument, Akamai relies on the statement in
BMC that “[a] party cannot avoid infringement . . . simply
by contracting out steps of a patented process to another
entity,” 498 F.3d at 1381.
    Akamai’s reliance on this statement is misplaced. As
discussed above, Limelight’s customers decide what
content, if any, they choose to have delivered by Lime-
light’s CDN and only then perform the “tagging” and
“serving” steps. The form contract does not obligate
Limelight’s customers to perform any of the method steps.
It merely explains that customers will have to perform
28   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



the steps if they decide to take advantage of Limelight’s
service. Because the customers were acting for their own
benefit, Limelight is not vicariously liable for the custom-
ers’ actions. See BMC, 498 F.3d at 1379 (holding that
liability exists only where the accused infringer has
“someone else carry out one or more of the claimed steps
on its behalf”); Muniauction, 532 F.3d at 1329 (“mere
‘arms-length cooperation’ will not give rise to direct
infringement by any party”) (quoting BMC, 498 F.3d at
1381).
    In the present case, the asserted claims were drafted
so as to require the activities of both Limelight and its
customers for a finding of infringement. Thus, Akamai
put itself in a position of having to show that the allegedly
infringing activities of Limelight’s customers were at-
tributable to Limelight. Akamai did not meet this burden
because it did not show that Limelight’s customers were
acting as agents of or otherwise contractually obligated to
Limelight or that they were acting in a joint enterprise
when performing the tagging and serving steps. Accord-
ingly, we affirm the district court’s grant of Limelight’s
motion for JMOL of non-infringement under § 271(a).
                     IV. CONCLUSION
     For the foregoing reasons, this court affirms the dis-
trict court’s grant of Limelight’s motion for JMOL of non-
infringement of the ’703 patent.
    Limelight argues as an alternative ground for affir-
mance that Akamai presented no substantial evidence
that Limelight or its customers actually performed the
tagging limitation as properly construed. Because we find
that the district court properly granted JMOL of nonin-
fringement on the ground stated, we need not and do not
address this argument. Likewise, we do not reach Lime-
light’s conditional cross-appeal of the damages award
alleging that Akamai failed to present economic proof of a
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   29



causal link between Limelight’s infringement and any
Akamai lost sales.
    We also confirm our previously reinstated affirmance
of the district court’s judgment of noninfringement of
the ’413 and ’645 patents.
                     AFFIRMED
  United States Court of Appeals
      for the Federal Circuit
                 ______________________

        AKAMAI TECHNOLOGIES, INC.,
      THE MASSACHUSETTS INSTITUTE OF
               TECHNOLOGY,
              Plaintiffs-Appellants

                            v.

           LIMELIGHT NETWORKS, INC.,
              Defendant-Cross-Appellant
               ______________________

      2009-1372, 2009-1380, 2009-1416, 2009-1417
               ______________________

    Appeals from the United States District Court for the
District of Massachusetts in Nos. 06-CV-11585, 06-CV-
11109, Judge Rya W. Zobel.
                ______________________

MOORE, Circuit Judge, dissenting.
    Today the majority holds that the actions of multiple
parties can only result in direct infringement of a method
claim in three circumstances: in a principal-agent rela-
tionship, in a contractual arrangement, or in a joint
enterprise functioning as a form of mutual agency. It
divorces patent law from mainstream legal principles by
refusing to accept that § 271(a) includes joint tortfeasor
liability. The majority’s rule creates a gaping hole in
what for centuries has been recognized as an actionable
form of infringement. It claims that this result is man-
dated by the statute. I do not agree. The single entity
2    AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



rule promulgated in BMC and Muniauction is a recent
judicial creation inconsistent with statute, common law,
and common sense. For centuries, the concerted actions
of multiple parties to infringe a patent gave rise to liabil-
ity. The plain language of § 271(a) codified this joint
infringement. To construe that language otherwise would
permit identical language in the statute to have incon-
sistent meanings. Congress meant to and did codify
liability for joint infringement. It did not, as the majority
suggests, purposefully do away with a broad swath of
recognized forms of liability for infringement. I respect-
fully dissent from the majority’s decision to interpret
§ 271(a) in a manner that condones the infringing conduct
in this case.
    Without the innovative technology protected by the
patent-in-suit, the Internet as we know it would not exist.
In the mid-1990s, the Internet was exploding. Ever
increasing numbers of users were sharing increasingly
bandwidth-heavy information, often at great distances.
From text to photos to music and videos, users were
placing exponentially greater pressure on the infrastruc-
ture of the Internet. Congestion and interruptions in
service were standard.
    Mirroring, where an entire website is replicated on
multiple servers in multiple locations, was a known
solution to some of these problems. However, mirroring
came with problems of its own. Mirroring was not scala-
ble, and content providers had less control over mirrored
data stored on servers in distant locations. Because of the
overhead required to synchronize mirrored websites at
multiple locations, mirroring was inefficient for websites
with dynamic information.
    Dr. Tom Leighton, a professor of theoretical mathe-
matics at MIT, and Danny Lewin, his research assistant,
solved these problems. They developed a scalable net-
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   3



work of mirrored, geographically distributed servers for
delivering content (content delivery network or CDN). To
direct requests for this content, they developed a domain
name system that could intelligently select a suitable
CDN server from which the user could obtain the request-
ed content. And they developed a method by which con-
tent providers could “tag” content to be delivered by the
CDN, rather than their own servers. Using their inven-
tion, a content provider like ESPN could serve the text of
its website (with news articles updated in real time) from
its own servers and tag static, bandwidth-heavy content
(such as photos and videos accompanying a news article)
to be served by the CDN, reducing the burden on ESPN’s
server. Dr. Leighton and Mr. Lewin’s invention promised
efficient, scalable delivery of tagged content while main-
taining a content provider’s flexibility and control over
other content.
    To protect their innovation, Dr. Leighton and Mr.
Lewin patented their invention. They then founded
Akamai, the exclusive licensee of the patent-in-suit, U.S.
Patent No. 6,108,703. Akamai was an immediate success,
and its dramatically improved method of delivering
content was compared to “great historical shifts—
discoveries of better, faster ways—like the invention of
Arabic numerals, or the development of seafaring.” Paul
Spinrad, The New Cool: Akamai Overcomes the Internet’s
Hot Spot Problem, WIRED (Aug. 1999), available at
http://archive.wired.com/wired/archive/7.08/akamai_pr.ht
ml.
    In response to Akamai’s success, competitors began
copying Akamai’s methods of distributing content. Lime-
light, founded a few years after Akamai, is one such
competitor. A jury found that Limelight, in collaboration
with its content provider customers, practices every step
of the methods disclosed in four claims of the ’703 patent.
For example, of the four steps of claim 34 of the ’703
4    AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



patent, Limelight performs every step save one: the
“tagging” step. This step is performed by Limelight’s
customers, who tag the content to be hosted and delivered
by Limelight’s CDN. Limelight instructs its customers
how to tag, and employees are on call if its customers
require additional assistance. Moreover, Limelight re-
quires all of its customers to sign a standard contract.
The contract delineates the steps that must be performed
by these customers if they use the Limelight service—
steps that include tagging content. When Limelight’s
content delivery customer chooses to use Limelight’s CDN
to deliver web content to Internet users, it must tag
content. It has no choice: if it wishes to use the product, it
must tag content. Limelight itself then performs all of the
other steps of Akamai’s patent claims. Thus, every time
Limelight’s service is used, all the claim steps of Akamai’s
patent are performed as part of the Limelight CDN ser-
vice.
    When Dr. Leighton and Mr. Lewin patented their in-
vention, they expected our legal system to protect their
intellectual property. For all of history, a company that
did what Limelight had done would be liable for patent
infringement. Limelight performed all but one step of a
patented method, and Limelight directed its customers to
perform that final step. Both Limelight and its customers
obtained the economic benefits of performing all of the
steps of the claimed patent—namely, faster, more effi-
cient delivery of tagged content coupled with control and
flexibility over untagged content. To say Limelight has
not committed the tort of patent infringement is incon-
sistent with the common law, the plain language of the
Patent Act, and centuries of patent law that preceded
BMC and Muniauction.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   5



I.   The Creation of the Single Entity Rule and the Direc-
                   tion or Control Test
    The majority’s ruling today rests on its application of
one rule—the single entity rule—and its interpretation of
another—the direction or control test. Before explaining
why the majority’s view of these rules are inconsistent
with the statute, it is helpful to briefly explain the man-
ner by which they came into being.
    BMC treated the single entity rule as if it were a first
principle, proclaiming that “[i]nfringement requires, as it
always has, a showing that a defendant has practiced
each and every element of the claimed invention.” BMC
Res., Inc. v. Paymentech, L.P., 498 F.3d 1373, 1380 (Fed.
Cir. 2007). It concluded—without analysis—that the
single entity rule was derived from the use of the term
“whoever” in § 271(a). Id. To support this seemingly age-
old proposition, BMC cited to the Supreme Court’s hold-
ing in Warner-Jenkinson Co. v. Hilton Davis Chemical
Co., 520 U.S. 17, 40 (1997), that the doctrine of equiva-
lents should be performed on an element-by-element
basis. BMC, 498 F.3d at 1380. As commentators have
noted, Warner-Jenkinson’s discussion of the all elements
rule does not support the much narrower proposition that
BMC attributed to it. See, e.g., W. Keith Robinson, No
“Direction” Home: An Alternative Approach to Joint
Infringement, 62 AM. U. L. REV. 59, 86 (2012); Damon
Gupta, Virtually Uninfringeable: Valid Patents Lacking
Protection Under the Single Entity Rule, 94 J. PAT. &
TRADEMARK OFF. SOC’Y 61, 63 n.32 (2012); see also Dennis
Crouch, Joint Infringement: When Multiple Actors Work
in     Concert,    Patently–O       (Apr.    14,     2011),
http://www.patentlyo.com/patent/2011/04/joint-
infringement-when-multiple-actors-work-in-concert.html
(“In several post-1952 cases, the Supreme Court has
stated that an invention must actually be infringed—i.e.,
practiced—before someone can be liable for indirect
infringement. However, in those cases, the Supreme
6   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



Court did not state that the actual infringement must be
performed by a single entity.”). Further, as the amici and
commentators have noted, there does not appear to be any
precedential support for the single entity rule. Brief of
Amicus Curiae Pharmaceutical Research and Manufac-
turers of America at 8, Akamai Techs., Inc. v. Limelight
Networks, Inc., 692 F.3d 1301 (Fed. Cir. 2012) (en banc)
(No. 09-1372) (“[T]here is no longstanding or properly
considered rule that requires all the steps of a method
claim to be performed by a single actor, and there is a
significant body of law that holds otherwise.”) (“Pharma-
ceutical Research Amicus Brief”); Brief of Amicus Curiae
Biotechnology Industry Organization at 23, Akamai, 692
F.3d 1301 (No. 09-1372) (“Nothing in Supreme Court
jurisprudence indicates that the predicate act of direct
infringement can only be undertaken by a single entity.”)
(“Biotechnology Amicus Brief”); W. Keith Robinson, No
“Direction” Home: An Alternative Approach to Joint
Infringement, 62 AM. U. L. REV. 59, 86 (2012) (noting that
“none of these cases [relied on by BMC] explicitly state
that ‘a single entity’ must perform each and every step of
a claimed method to be a direct infringer.”); Brett M.
Jackson, Bridging the (Liability) Gap: The Shift Toward
§ 271(b) Inducement in Akamai Represents a Partial
Solution to Divided Infringement, 54 B.C. L. REV. 2127,
2151 (2013) (discussing the “‘single entity’ rule announced
in BMC”).
    With scant analysis, the single entity rule was born.
To the extent there was any confusion about the use of
the term “a defendant” in BMC, the court’s Muniauction
decision made clear that “direct infringement requires a
single party to perform every step of a claimed method.”
Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318, 1329
(Fed. Cir. 2008) (emphasis added). Both BMC and Mu-
niauction explain that whether the combined acts of
multiple parties should be attributed to a single entity is
determined by the “direction or control” test—“where the
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.    7



actions of multiple parties combine to perform every step
of a claimed method, the claim is directly infringed only if
one party exercises ‘direction or control’ over the entire
process such that every step is attributable to the control-
ling party, i.e. the ‘mastermind.’” Muniauction, 532 F.3d
at 1329 (quoting BMC).
    Neither of these cases supports the claim that the
single entity rule is some longstanding, well-accepted
principle. A host of amici and commentators agree that
BMC and Muniauction’s pronouncement of the single
entity rule changed the law, vitiated broad classes of
patents, and created a gaping loophole in infringement
liability. Brief of Amicus Curiae Boston Patent Law
Association at 1, Akamai, 692 F.3d 1301 (No. 09-1372)
(“[The single entity rule] improperly and unnecessarily
renders worthless an entire class of interactive method
patents and will undermine the public’s confidence in
patents and in the patent system as a whole.”); Brief of
Amicus Curiae Cascades Ventures, Inc. at 5–6, 11, Aka-
mai, 692 F.3d 1301 (No. 09-1372) (“[BMC and Muniauc-
tion] have changed the law to create a gaping hole in
liability for patent infringement” and the Akamai panel
decision has “destroyed thousands of duly issued patent
claims.”) (“Cascades Amicus Brief”); Brief of Amicus
Curiae Myriad Genetics, Inc. at 2–3, Akamai, 692 F.3d
1301 (No. 09-1372) (noting that strict application of the
single entity rule “encourages collusion among collaborat-
ing parties to escape infringement liability[,] eviscerates a
large number of method patent claims in the field of
personalized medicine, as well as many other fields, and
significantly weakens the U.S. patent system”) (“Myriad
Amicus Brief”); Biotechnology Amicus Brief at 9–10
(“[T]his Court’s single entity rule invites would-be in-
fringers to circumvent a particularly valuable subset of
biotechnology patents by ‘dividing up’ steps of patented
methods for separate practice, and avoiding the kinds of
8    AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



formal legal relationships that were only recently estab-
lished by this Court as a predicate to infringement liabil-
ity.”); Stacie L. Greskowiak, Joint Infringement After
BMC: The Demise of Process Patents, 41 LOY. U. CHI. L.J.
351, 403 (2010) (“Without judicial recourse, the ‘direction
or control’ standard will render thousands of socially
valuable and otherwise valid process patents unenforcea-
ble.”); Alice Juwon Ahn, Finding Vicarious Liability in
U.S. Patent Law: The “Control or Direction” Standard for
Joint Infringement, 24 BERKELEY TECH. L.J. 149, 171
(2009) (“[M]any thousands of patents may become worth-
less under the stringent ‘control or direction’ standard set
forth in the Muniauction decision.”); Long Truong, After
BMC Resources, Inc. v. Paymentech, L.P.: Conspiratorial
Infringement as a Means of Holding Joint Infringers
Liable, 103 NW. U. L. REV. 1897, 1899 (2009) (“The loop-
hole [created by BMC] is a serious one. It encourages
potential infringers of process patents to enter into con-
spiracies to circumvent infringement liability by dividing
steps among the parties so long as there is no controlling
or directing party.”); Dolly Wu, Joint Infringement and
Internet Software Patents: An Uncertain Future?, 91 J.
PAT. & TRADEMARK OFF. SOC’Y 439, 441 (2009) (“The
[Muniauction] decision creates a catch-22 situation be-
cause it is unlikely for vicarious liability relationships to
exist across the Internet. Due to Muniauction, not only
are many Internet software patents now unenforceable,
but many other network and communication patents may
also be unenforceable.”).
    That many patentees crafted their patent claims in a
manner that is incapable of being infringed belies the
proposition that there was a long-standing single entity
requirement for direct infringement. I do not agree with
the majority that this patent, and the thousands of other
patents across many different industries, drafted in a
manner which contemplated joint infringement liability,
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   9



are “poorly-drafted.” Maj. at 17. Instead, we have
changed the rules on these folks. Clarity is not a virtue
we can claim in this particular scenario.
     II. Joint Infringement Liability Under § 271(a)
    Section 271 defines the requirements for infringe-
ment. This case is first, last, and entirely about statutory
construction. Section 271(a) provides that: “whoever
without authority makes, uses, offers to sell, or sells any
patented invention, within the United States or imports
into the United States any patented invention during the
term of the patent therefor, infringes the patent.” 35
U.S.C. § 271(a). All agree that infringement of a process
claim requires each claimed step to be performed—that is
how the process is “use[d].” Nothing about joint infringe-
ment changes or undermines the all elements rule. For
infringement to occur, all the elements or steps must be
performed. The dispute here is about who must perform
those steps. That dispute centers around the meaning of
“whoever.”
     “Whoever,” as used in § 271(a), encompasses multiple
entities. Dictionaries define “whoever” in the plural as
“[w]hatever person or persons.” Principal Brief for Plain-
tiff-Appellant Akamai on Rehearing En Banc at 15,
Akamai, 692 F.3d 1301 (No. 09-1372) (quoting American
Heritage College Dictionary 1540 (3d ed. 1997)); Brief of
Amicus Curiae AIPLA at 11, Limelight Networks, Inc. v.
Akamai Techs., Inc., 134 S. Ct. 2111 (2014) (No. 12-786)
(quoting American Heritage Dictionary of the English
Language (4th ed. 2000)) (“AIPLA Amicus Brief”). The
Dictionary Act states that “words importing the singular
include and apply to several persons, parties, or things,”
and it expressly defines “whoever” as including plural
entities: “the words ‘person’ and ‘whoever’ include corpo-
rations, companies, associations, firms, partnerships,
societies, and joint stock companies, as well as individu-
10   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



als.” 1 U.S.C. § 1. By its plain language, the phrase
“whoever . . . makes, uses, offers to sell, or sells any
patented invention . . . infringes the patent” means “any
person or persons who make, use, offer to sell, or sell any
patented invention infringe the patent.”
     The word “whoever” appears in other sections of the
Patent Act, and in each case the word “whoever” expressly
includes the collective actions of multiple persons. Identi-
cal terms are presumed to have the same meaning within
a statute, even if the terms appear in different sections.
Sullivan v. Stroop, 496 U.S. 478, 484 (1990) (“[T]he nor-
mal rule of statutory construction [is] that identical words
used in different parts of the same act are intended to
have the same meaning.”); see also Antonin Scalia &
Bryan A. Garner, Reading Law: The Interpretation of
Legal Texts 170–73 (2012) (“A word or phrase is presumed
to bear the same meaning throughout a text . . . . Th[is]
presumption . . . applies also when different sections of an
act or code are at issue.”). 35 U.S.C. § 101 states that
“whoever invents or discovers any new and useful process
. . . may obtain a patent therefor . . . .” All agree that
“whoever” in § 101 includes joint inventors. See 35 U.S.C.
§ 116(a); see also 35 U.S.C. §§ 161, 171. One can be a joint
inventor, and thus within the meaning of “whoever in-
vents,” as long as he contributes to the conception of the
invention, even if he does not conceive of the entire inven-
tion. Vanderbilt Univ. v. ICOS Corp., 601 F.3d 1297,
1303 (Fed. Cir. 2010); Eli Lilly & Co. v. Aradigm Corp.,
376 F.3d 1352, 1359 (Fed. Cir. 2004). It follows, then,
that “whoever . . . uses” a process for the purposes of
infringement covers multiple parties who act in concert to
collectively perform the claimed process, even though they
may not individually practice each step.
    The majority gives little consideration to the text of
the statute, relegating its discussion of “whoever” to a
footnote. It does not consider principles of statutory
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   11



construction or attempt to reconcile its construction with
the other uses of “whoever” in the same statute. The
majority posits that the fact that whoever is plural means
only that more than one entity can be liable for patent
infringement. This construction assigns no weight to the
plural form because the same would be true if the singu-
lar were used. For example, if the statute read “one who
uses” a patented invention, all would agree that two
people performing each step of the patented process would
each be liable for infringement. No one would claim that
once the first person infringed, the second could not be
liable for infringement.      The majority’s construction
makes no sense and is inconsistent with the statute’s use
of “whoever” in 35 U.S.C. §§ 101, 161, and 171, which all
undeniably reference joint inventors, meaning multiple
parties acting together.
   The plain language and contextual analysis compel the
conclusion that “whoever” within the context of § 271(a)
includes joint infringers—multiple entities acting in
concert pursuant to a common plan or purpose (joint
tortfeasors). Moreover, the presumption against ineffec-
tiveness supports construing “whoever” to include joint
infringement. If “language is susceptible of two construc-
tions, one of which will carry out and the other defeat its
manifest object, the statute should receive the former
construction.” Antonin Scalia & Bryan A. Garner, Read-
ing Law: The Interpretation of Legal Texts 63 (2012)
(quoting Citizen Bank of Bryan v. First State Bank, 580
S.W.2d 344, 348 (Tex. 1979)) (alterations omitted). Con-
struing “whoever” as the majority does creates a “gaping
loophole” in our infringement law that sanctions infring-
ing activity and “renders issued and future patents in
important technologies virtually unenforceable.” AIPLA
Amicus Brief at 9. See also Biotechnology Amicus Brief at
13 (“[B]oth common sense and the patent law’s purpose
would be defeated if joint actors were allowed to divide up
12   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



the practice of a patented invention in circumvention of
the patentee’s rights.”); Myriad Amicus Brief at 11 (“The
Federal Circuit’s recent decisions on so-called ‘joint in-
fringement’ have taken a restrictive approach and, in so
doing, have created a loophole for would-be infringers.”);
Damon Gupta, Virtually Uninfringeable: Valid Patents
Lacking Protection Under the Single Entity Rule, 94 J.
PAT. & TRADEMARK OFF. SOC’Y 61, 68, 74 (2012) (explain-
ing that the Federal Circuit’s single entity rule “has
created an incongruous result—some patents are virtually
uninfringeable. . . . This creates a loophole where a de-
fendant can collaborate with others to collectively perform
every step of the patented process and avoid liability for
infringement.”).
     For example, consider the following scenario. Party A
intentionally induces party B to perform each and every
step of a method claim. Unquestionably, party B is a
direct infringer under § 271(a) and party A is an inducer
under § 271(b). Switching the facts only slightly, assume
that party A performs the first step in the claimed method
and then, with the same knowledge and intent, induces
party B to perform the remaining steps. Under the major-
ity’s rule, neither party is liable, even though the harm to
the patentee remains the same. Party A is not even liable
as an inducer because, under the single entity rule, no
direct infringement has occurred. Limelight, 134 S. Ct. at
2117 (“[W]here there has been no direct infringement,
there can be no inducement of infringement.”). To apply
the majority’s construction “would be rendering the law in
a great measure nugatory, and enable offenders to elude
its provisions in the most easy manner.” The Emily & the
Caroline, 22 U.S. (9 Wheat.) 381 (1824) (Thompson, J.).
Indeed, the Supreme Court recognized that the loophole
may have arisen from “the possibility that the Federal
Circuit erred by too narrowly circumscribing the scope of
§ 271(a).” Limelight, 134 S. Ct. at 2119.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   13



    The majority claims that this gaping hole in liability,
which the majority never defends, and which all agree
makes no sense, was “Congress’ deliberate choice.” Ac-
cording to the majority, “Congress carefully crafted sub-
sections (b) and (c)” and intentionally “removed joint-actor
patent infringement liability.” Maj. at 10–11. The major-
ity recognizes that “[a]t the time, the common law con-
tained myriad other theories of infringement, such as, for
example, those in Peerless and Solva. In enacting § 271(b)
and (c), Congress cleared away the morass of multi-actor
infringement.” Maj. at 11 (full cites omitted). 1 It has
been generally understood that with regard to infringe-
ment, the 1952 Patent Act was not meant to make sweep-
ing changes to the scope of liability, but rather to codify
existing infringement liability and restore notions of
infringement which had been curtailed by the Supreme
Court’s decisions in Mercoid Corp. v. Mid-Continent
Investment Co., 320 U.S. 661 (1944), and Mercoid Corp. v.
Minneapolis-Honeywell Regulator Co., 320 U.S. 680
(1944).
    The majority never explains why Congress would in-
tentionally do away with joint infringement liability and
create what is universally recognized as a gaping hole in
liability. No party or amici defends as logical the rule


   1    Even amici who suggest that § 271(a) does not in-
clude joint infringement admit that such a result was
likely never intended by Congress. See, e.g., Brief of
Amicus Curiae United States at 14, Limelight, 134 S. Ct.
2111 (No. 12-786) (“As a matter of patent policy, there is
no obvious reason why a party should be liable for induc-
ing infringement when it actively induces another party
to perform all the steps of the process, but not liable when
it performs some steps and induces another party to
perform the rest. . . . The statutory gap is unfortunate.”)
(“US Amicus Brief”).
14       AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



which the majority says Congress intentionally adopted:
that when one induces another to perform the steps of a
patented method both parties are liable; however, when
one performs some of the steps and induces another to
perform the remaining steps, nobody is liable. The harm
to the patentee is identical in either case—the entire
method has been performed—and the joint tortfeasors
have received the economic benefit of that patented
method.
    The majority’s primary criticism of interpreting “who-
ever” in § 271(a) to include joint infringers is that doing so
would render §§ 271(b) and (c) superfluous. This is simply
wrong. Sections 271(b) and (c) would still apply in situa-
tions where § 271(a) would not. AIPLA Amicus Brief at
17–20. Consider the same scenario discussed previous-
ly—where one party induces another to perform all steps
of a claimed method. That party has undisputedly in-
fringed under § 271(b). It is not, however, liable for direct
infringement under § 271(a) because it has not performed
any step of the claimed method. Section 271(a), by its
own terms, does not apply to an entity that does not
perform any step of a patented method, because that
party would not be one of the person or persons who
jointly “uses” the method within the meaning of the
statute. 2 See NTP, Inc. v. Research In Motion, Ltd., 418



     2  It is an unassailable truism that an entity who
does not perform any method steps is not using the meth-
od, not individually and not jointly. The majority also
claims that this unremarkable definition of “use” would be
at odds with common law tort principles because it would
exclude inducers who encourage another’s use without
themselves performing steps. But isn’t this exactly what
Congress did cover in § 271(b)? I am not sure how Con-
gress’ choice to divide joint tortfeasor acts giving rise to
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   15



F.3d 1282, 1318 (Fed. Cir. 2005) (“Because a process is
nothing more than the sequence of actions of which it is
comprised, the use of a process necessarily involves doing
or performing each of the steps recited.”); see also AIPLA
Amicus Brief at 18 (“Section 271(a) does not apply to an
entity that performs no steps of a patented method.”);
Bauer & Cie v. O’Donnell, 229 U.S. 1, 10–11 (1913) (“The
right to use is a comprehensive term and embraces within
its meaning the right to put into service any given inven-
tion.”). As this example demonstrates, §§ 271(b) and (c)
are not at all rendered superfluous. The majority’s claim
that I have “manufactured a single case” so as not to
“render § 271(b) superfluous” is confusing. Sections
271(b) and (c) would continue to apply and be the exclu-
sive avenue for liability where the inducer or contributor
did not perform any of the steps themselves. Rather than
being an off-the-mark single example, this example is the
fact pattern of every §§ 271(b) and (c) case ever decided.
No case ever decided under § 271(b) or (c) would come out
differently, nor would any of those fact patterns give rise
to § 271(a) liability, under my construction. Nothing is
superfluous.
     The plain language of § 271(a) and the accompanying
sections of the Patent Act make clear that “whoever . . .
uses” a process includes joint infringers just as “whoever
invents” includes joint inventors. And despite the majori-
ty’s pronouncement, this standard is not limited to parties
acting as part of a principal-agent relationship, a contrac-
tual arrangement, or a joint enterprise. The statutory
language, the common law, and our case law are not so
limiting. Joint infringement encompasses an infringer
who performs some claim steps and directs or controls



liability among the three sections (a), (b), and (c) is “un-
tenable.” Maj. at 9.
16   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



another to perform the remainder of the claimed process
and it includes parties who act in concert to collectively
perform the claimed process pursuant to a common plan,
design, or purpose. Liability for such multi-actor joint
infringement was present and widely recognized in the
common law prior to the 1952 Patent Act, and continues
to be present in § 271(a).
    The majority suggests that its construction is correct
despite the fact that it renders the use of “whoever” in the
Patent Act internally inconsistent and without consider-
ing, or even admitting, that it creates a gaping hole in
liability that had not previously existed in the common
law. Instead, the majority claims that this was purpose-
ful and intentional by Congress because, in 1952, Con-
gress sought to do away with all commonly recognized
forms of joint infringement except that codified in
§§ 271(b) and (c). Section 271(a)’s use of “whoever” ex-
pressly includes joint infringement as §§ 101, 161, and
171’s use of “whoever” includes joint invention. The plain
language of the statute indicates that Congress chose to
divide joint tortfeasor acts giving rise to liability among
the three sections (a), (b), and (c). This construction gives
meaning to all the words in the statute, interprets the
word “whoever” consistently, and reflects Congress’ codifi-
cation of the state of liability for infringement prior to the
creation of the 1952 Patent Act.
         III. The Common Law Supports § 271(a)
                Joint Infringement Liability
    The Supreme Court observed in Aro Manufacturing
Co. v. Convertible Top Replacement Co., 365 U.S. 336, 342
(1961) that “§ 271(a) of the new Patent Code, which
defines ‘infringement,’ left intact the entire body of case
law on direct infringement.” The common law prior to the
1952 Patent Act recognized joint liability for patent
infringement in a broader set of circumstances than
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   17



proposed today by the majority, such as where one party
directs or controls the actions of another to infringe a
patent, or where two parties act in concert to perform the
claimed method steps pursuant to a common goal, plan, or
purpose. As summarized by Robinson’s famous patent
treatise, “[a]n act of infringement is committed by mak-
ing, using, or selling the patented invention without
authority from the owner . . . or by acting in complicity
with others under any cover or pretence the practical
effect of which is an invasion of the monopoly created by
the patent. All who perform or who unite in the perfor-
mance of an act of infringement, by any of these methods,
may be sued jointly and severally.” 3 William C. Robin-
son, The Law of Patents for Useful Inventions § 946 (1890)
(“Robinson”). Similarly, another treatise explained that
“[w]hoever directs or requests another to infringe a pa-
tent, is himself liable to an action for the resulting in-
fringement,” and “[w]here several persons co-operate in
any infringement, all those persons are liable therefor as
contributors thereto.” Albert H. Walker, Textbook of the
Patent Laws of the United States of America (4th ed. 1904)
(“Walker”). 3




   3     Joint infringement is not a “relatively new prob-
lem.” US Amicus Brief at 31; see also id. at 14 (“[T]he
current provisions of Section 271 do not deal adequately
with the relatively new phenomenon in which multiple
parties collectively practice the steps of a patented meth-
od.”). From the earliest patent treatises throughout the
legislative history of the 1952 Patent Act and continuing
to the thousands of current patents whose claims are
drafted to cover joint infringement, the practice of multi-
ple parties acting in concert to perform the steps of a
patented method has been known and cognizable. See
Walker, supra; Robinson, supra (both acknowledging that
18   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



     Several of the pre-1952 cases cited by the parties rec-
ognize joint infringement liability. In York & Maryland
Line Railroad Co. v. Winans, the Supreme Court held that
a company that owned the rails on which a different
company operated infringing cars for both companies’
profits was liable for infringement because it was “a
principal, cooperating with another corporation, in the
infliction of a wrong, and is directly responsible for the



if “several persons cooperate in any infringement” they
are all liable); Contributory Infringement: Hearings on
H.R. 3866 Before Subcomm. No. 4 of the House Comm. on
the Judiciary, 81st Cong. 3 (1949) (statement of G. Rich)
(“[W]hen two people combine and infringe a patent in
some way or other, they are joint tort feasors, and it so
happens that patents are often infringed by people acting
in concert, either specifically or by implication.”); Con-
tributory Infringement in Patents: Hearings Before Sub-
comm. on Patents, Trade-marks, and Copyrights of the H.
Comm. on the Judiciary, 80th Cong. 5 (1948) (statement
of G. Rich on behalf of the New York Patent Law Associa-
tion) (arguing in favor of adoption of the 1952 Patent Act
in order to establish liability where a patented method is
performed by two or more persons acting in concert: “a
new method of radio communication may involve a change
in the transmitter and a corresponding change in the
receiver. To describe such an invention in patent claims,
it is necessary either to specify a new method which
involves both transmitting and receiving, or a new combi-
nation of an element in the receiver and an element in the
transmitter . . . The recent decisions of the Supreme Court
appear to make it impossible to enforce such patents in
the usual case where a radio transmitter and a radio
receiver are owned and operated by different persons.”).
Joint infringement is not a new problem nor is it one that
escaped Congress’ attention in 1952.
AKAMAI TECHNOLOGIES, INC.    v. LIMELIGHT NETWORKS, INC.      19



resulting damage.” 58 U.S. 30, 40 (1854). Similarly, in
Jackson v. Nagle, a contractor that performed certain
infringing steps and a subcontractor that performed the
remaining infringing steps were held liable as “joint
infringers.” 47 F. 703 (C.C.N.D. Cal. 1891). 4 See also
Thomson-Houston Elec. Co. v. Ohio Brass Co., 80 F. 712,
721 (6th Cir. 1897) (“An infringement of a patent is a tort
analogous to trespass or trespass on the case. From the
earliest times, all who take part in a trespass, either by
actual participation therein or by aiding and abetting it,
have been held to be jointly and severally liable for the
injury inflicted. . . . If this healthful rule is not to apply to
trespass upon patent property, then, indeed, the protec-
tion which is promised by the constitution and laws of the
United States to inventors is a poor sham.”); New Jersey
Patent Co. v. Schaeffer, 159 F. 171, 173 (C.C.E.D. Pa.
1908) (“Where an infringement of a patent is brought
about by concert of action between a defendant and com-
plainants’ licensee, all engaged directly and intentionally
become joint infringers.”); Wallace v. Holmes, 29 F. Cas.
74, 80 (C.C.D. Conn. 1871) (If, “in actual concert,” one
party consents to manufacture a first part of a claimed
combination, and another party makes the second part,
both “are tort-feasors, engaged in a common purpose to




    4   The majority discounts Jackson and other pre-
1952 cases on the basis that they did not deal with meth-
od claims. The language of the patent statute draws no
distinctions between method and machine claims to
indicate that Congress intended joint tortfeasor concepts
to be incorporated into infringement liability when ma-
chine claims are at issue, but not when method claims are
at issue. These cases indicate that concerted action
amounted to joint infringement and was actionable at the
time.
20   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



infringe the patent, and actually, by their concerted
action, producing that result.”).
    Two other pre-1952 cases from the Seventh Circuit
confirm the understanding that the concerted actions of
two different parties can result in direct infringement of a
method claim. In Peerless Equipment Co. v. W. H. Miner,
Inc., the defendant manufacturer performed all but the
last step of the claimed method, which was performed by
the defendant’s customer. 93 F.2d 98, 105 (7th Cir. 1937).
Despite the divided infringement scenario, the Seventh
Circuit found the defendant liable for contributory in-
fringement. Id. Similarly, in Solva Waterproof Glue Co.
v. Perkins Glue Co., the defendant was held liable for
contributory infringement where the defendant’s custom-
er performed one step of the two-step process. 251 F. 64,
73 (7th Cir. 1918). For the defendants in both cases to be
liable for contributory infringement, there must have
been some underlying direct infringement. Limelight, 134
S. Ct. at 2117 (“[O]ur case law leaves no doubt that in-
ducement liability may arise ‘if, but only if, [there is] . . .
direct infringement.’”) (quoting Aro, 365 U.S. at 341).
This requirement existed before the 1952 Patent Act.
Aro, 365 U.S. at 341 (“It is plain that § 271(c)—a part of
the Patent Code enacted in 1952—made no change in the
fundamental precept that there can be no contributory
infringement in the absence of a direct infringement.”).
Peerless and Solva implicitly—but necessarily—held that
two parties’ performance of different steps of the claimed
methods constituted direct infringement of those methods.
    Certainly, some of the pre-1952 principles and cases
cited above are more akin to what we today consider to be
indirect infringement rather than direct infringement
under § 271(a). But they all gave rise to liability and the
1952 Patent Act codified all of them. In §§ 271(b) and (c),
it codified certain grounds for induced and contributory
infringement. And in § 271(a), by using the plural term
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   21



“whoever,” it codified the common law rule that two
parties who act in concert pursuant to a common plan or
design to perform a claimed method are liable for joint
infringement.
     Interpreting § 271(a) to allow for infringement by the
concerted action of multiple parties is consistent with
general common law principles of tort liability. The
common law imposed joint liability when two or more
parties acted in concert—alternatively referred to as
concerted action or acting with another in pursuit of a
common plan, design, or purpose—even without an agen-
cy relationship or contractual obligation. “One is subject
to liability if he . . . does a tortious act in concert with
[an]other pursuant to a common design with him.” Re-
statement (Second) of Torts § 876(a); see also 1 Edwin A.
Jaggard, Hand-book of the Law of Torts § 67 (“[J]oint tort
feasors are held responsible, not because of any relation-
ship existing between them, but because of concerted
action toward a common end. . . . All persons who aid,
counsel, direct, or join in committing a tort are joint
tortfeasors.”). Indeed, the common law imposed liability
for harm resulting from multiple parties even if the
individual acts of each party were not tortious. Prosser &
Keeton on Torts § 52 (“A number of courts have held that
acts which individually would be innocent may be tortious
if they thus combine to cause damage.”); Fowler Vincent
Harper, A Treatise on the Law of Torts § 302 (1933)
(“Harper”) (“Joint liability in tort may be imposed in three
types of situations: (1) where the actors concur in the
performance of the tortious act or acts; (2) where, alt-
hough there is no joint action, nevertheless the independ-
ent acts of several actors concur to produce harmful
consequences; and (3) where by reason of some special
relationship between the parties, joint liability is im-
posed.”). The agreement to act in concert can be express,
implied, or a tacit understanding. Prosser & Keeton on
22   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



Torts § 46 (“Express agreement is not necessary, and all
that is required is that there be a tacit understanding.”);
Akamai, 692 F.3d at 1349 (Linn, J., dissenting) (agree-
ment can be express or implied); Restatement (Second) of
Torts § 876(a), cmt. a (“The agreement need not be ex-
pressed in words and may be implied and understood to
exist from the conduct itself.”).
     And while the post-1952 precedent is not a model of
clarity on the circumstances in which concerted action or
joint infringement creates liability under § 271(a), courts
frequently recognized liability under § 271(a) in joint
tortfeasor scenarios, not limited to vicarious liability. See,
e.g., On Demand Mach. Corp. v. Ingram Indus., Inc., 442
F.3d 1331, 1344–45 (Fed. Cir. 2006) (approving district
court’s jury instruction that “[i]t is not necessary for the
acts that constitute infringement to be performed by one
person or entity. . . . Infringement of a patented process or
method cannot be avoided by having another perform one
step of the process or method. Where the infringement is
the result of the participation and combined action(s) of
one or more persons or entities, they are joint infringers
and are jointly liable for the infringement.”); Hill v. Ama-
zon.com, Inc., No. 2:02-cv-186, 2006 WL 151911, at *2
(E.D. Tex. Jan. 19, 2006) (“In the absence of an agency or
contractual relationship, the case law appears to require a
showing that the defendant and the third party are con-
nected at least to the extent that the defendant must
actually direct the third party to perform the remaining
steps of the method.”); Shields v. Halliburton Co., 493 F.
Supp. 1376, 1389 (W.D. La. 1980) (“Infringement of a
patented process or method cannot be avoided by having
another perform one step of the process or method.”),
aff’d, 667 F.2d 1232 (5th Cir. 1982); see also Freedom
Wireless Inc. v. Boston Commc’ns Grp., Inc., No. 06-1020,
slip op. at 2–3 (Fed. Cir. Dec. 15, 2005) (noting district
court’s finding direct infringement under § 271(a) on a
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   23



theory of joint infringement where two different compa-
nies acted in concert to perform all the method steps and
instructing the jury: “if separate companies work together
to perform all of the steps of a claim of a patent, the
companies are jointly responsible, that is, responsible as a
group for the infringement of the patent. Even if no
single company performs all of the steps of a claim, the
companies are jointly responsible.”); Applied Interact,
LLC v. Vt. Teddy Bear Co., No. 04 Civ. 8713, 2005 WL
2133416, at *4 (S.D.N.Y. Sept. 6, 2005) (adopting a “some
connection,” not a vicarious liability, standard among
joint infringers); Marley Mouldings Ltd. v. Mikron Indus.,
Inc., No. 02 C 2855, 2003 WL 1989640, at *3 (N.D. Ill.
Apr. 30, 2003) (denying summary judgment of nonin-
fringement where parties collectively performed all meth-
od steps and holding that “[a] party cannot avoid
infringement merely by having another entity perform
one or more of the required steps when that party is
connected with the entity performing one or more of the
required steps”); Cordis Corp. v. Medtronic AVE, Inc., 194
F. Supp. 2d 323, 350 (D. Del. 2002), rev’d on other
grounds, 339 F.3d 1352 (Fed. Cir. 2003) (finding sufficient
evidence to support finding that there was “some connec-
tion” between two parties jointly performing method
claim); Faroudja Labs., Inc. v. Dwin Elecs., Inc., No. 97-
20010, 1999 WL 111788, at *5 (N.D. Cal. Feb. 24, 1999)
(recognizing that “a party [may be] liable for direct in-
fringement of a process patent even where the various
steps included in the patent are performed by distinct
entities” if there is “some connection between the different
entities”); Mobil Oil Corp. v. W.R. Grace & Co., 367 F.
Supp. 207, 253 (D. Conn. 1973) (holding that Grace direct-
ly infringed despite the fact that its customers performed
one of the claimed steps because “defendant, in effect,
made each of its customers its agent in completing the
infringement step knowing full well that the infringement
step would in fact be promptly and fully completed by
24   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



those customers”); Metal Film Co. v. Metlon Corp., 316 F.
Supp. 96, 110–11 (S.D.N.Y. 1970) (holding defendant
could not avoid direct infringement by having an outside
supplier perform one of the method steps). But see Mobil
Oil Corp. v. Filtrol Corp., 501 F.2d 282, 291–92 (9th Cir.
1974) (expressing doubt over the possibility of divided
infringement liability).
  IV. Applying the Statutory Interpretation to this Case
    Limelight is liable under § 271(a) for its actions and
the actions of its customers in infringing the ’703 patent.
First, Limelight is liable under the direction or control
test, because Limelight has performed a number of steps
of the patented methods, and it has directed its customers
to perform the remaining steps. Limelight is not an
innocent party who performed a single step. It is the
mastermind of the infringement in this case. It per-
formed all but one of the claim steps and it instructed, in
fact it required, its customers to perform the other claim
step before they could use Limelight’s content delivery
system. Such a person, personally responsible for the
performance of every claim step, has always been deemed
an infringer under the law. In these circumstances,
Limelight “uses” the patented method. Every time Lime-
light’s customers act, pursuant to its instruction to use its
content delivery system, infringement is occurring. All of
Akamai’s invention is used, all the claimed method steps
are performed, and all the economic benefit of Akamai’s
innovation is stolen. And Limelight is the one who profits
from this infringement. Limelight is using Akamai’s
patented invention and is responsible for the performance
of every patented step.
    Limelight could also be held liable as a joint infringer,
acting in concert with the customers pursuant to a com-
mon purpose, design, or plan. Limelight and its content
provider customers share a common purpose, design, or
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   25



plan: to provide website information to Internet users.
Limelight knowingly works together with its customers to
achieve that result, jointly performing all the steps of the
patented method and receiving exactly the economic
benefit secured by the patent. Limelight’s service im-
proves content delivery to Internet users, offering its
customers faster, more efficient delivery of tagged content
coupled with control and flexibility over untagged content.
A jury has found that all of the steps of the claims at issue
are performed by the collective actions of Limelight and
its customers. And these steps are performed in concert
pursuant to contract.
    Limelight requires all of its customers who wish to
use its service to sign a standard contract delineating the
actions that customers must perform to use the Limelight
service—actions that include steps of the patented meth-
od. The fact that Limelight did not tell its customers
what website content to tag is irrelevant to infringement
of the claims at issue, which do not discriminate among
tagged content. It is true that the contract does not
compel the customer to use Limelight’s service. But if the
customer does choose to use Limelight’s service to deliver
content, it must perform some of the claimed method
steps, and thus acts in concert with Limelight. The fact
that a customer may choose not to act in concert with
Limelight does not insulate Limelight from liability when
that customer actually chooses to do so.
     The Constitution and 35 U.S.C. § 154 grant patentees
the right to exclude others from using the patented inven-
tion in the United States. Akamai was undoubtedly
harmed—its entire patented process was used by others
for commercial gain all in the United States. This harm
is identical whether Limelight performed all the steps or
collaborated with its customers to divide them up. Lime-
light benefitted from the infringing use by selling its
services, which provided exactly the faster, more efficient
26       AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



content delivery system invented by Akamai. Limelight
knowingly performed each step except the tagging step,
and it knew that its customers would perform that tag-
ging step. Its content delivery system would not work
unless the customer performed the tagging step. In fact,
the contract it had with its customers required them to
perform that tagging step if they used the Limelight
service. Every step of the patented method was per-
formed and Limelight and its content provider customer
achieved exactly the economic benefit conferred by the
patent without having to pay a royalty for its use. Under
common law joint tortfeasor principles, Limelight’s con-
duct traditionally gave rise to liability. Under common
law patent principles, this conduct traditionally gave rise
to liability. For centuries, up until our recent decisions,
Limelight would have been liable for patent infringement.
And the majority makes no argument that Limelight
should not be held liable.
                  V. Responding to the Majority
    The majority’s creation of a narrow patent-specific
universe of joint infringement liability construes the
Patent Act in ways that are both internally inconsistent
and inconsistent with general tort principles. 5 Section
271(a) covers joint infringement, including situations
which give rise to joint tortfeasor liability. It includes
liability for a tortfeasor like Limelight who performed all
the method steps but one and then directed its customers
to perform the final step. The direction or control stand-


     5   Interestingly, the majority’s joint enterprise
standard is more akin to joint tortfeasor than agency. It
is discussed as a form of “vicarious liability.” However,
like other forms of joint tortfeasor liability and unlike
agency or contract obligation, it creates joint and several
liability among the participants of the joint enterprise.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   27



ard was not limited to situations where there was vicari-
ous liability at common law and there is no reason to read
such a limitation into § 271(a). Similarly, the common
law does not limit concerted action to instances where
parties are acting in furtherance of an agency relation-
ship, contractual obligation, or joint enterprise. See
Prosser & Keeton on Torts § 46; Restatement (Second) of
Torts § 876; Harper § 302.
     The majority cites a number of treatises for the propo-
sition that mere knowledge of another’s tortious activity is
not enough to give rise to liability. I agree. Joint tortfea-
sor liability requires concerted action pursuant to a com-
mon plan, purpose, or design. Joint tortfeasors are both
acting to create a single indivisible harm. I agree with
the majority that just knowing that someone else is acting
(when you yourself do nothing) does not subject you to
liability.
    And importantly, I am not importing a knowledge re-
quirement into § 271(a) that would be incompatible with
the strict liability nature of the tort of infringement.
There is no knowledge of the patent requirement under
§ 271(a) and neither my standard nor the majority’s
imports one.      Both standards, however, do require
knowledge to attribute the acts of one party to another.
The majority’s joint enterprise standard requires
knowledge, in fact, an agreement between the parties and
right of mutual control. Likewise, the joint tortfeasor
standard requires knowledge.            Neither requires
knowledge of the patent or knowledge of the harm that
will be caused. Rather, both adopt the common sense
principle that a party cannot be held liable for the actions
of another without knowing of that party’s actions and
some form of agreement or direction or control. Here
there is no dispute that Limelight itself acted (performed
all but one of the method steps) and knew precisely the
actions its customers would take and, in fact, it instructed
28   AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



them as to how to take those actions. This undoubtedly
comports with any knowledge requirement under joint
tortfeasor law that would attribute to Limelight those
acts taken by its customers.
     The majority criticizes the dissent for not incorporat-
ing into § 271(a) all joint tortfeasor scenarios. The answer
is clear: not all joint tortfeasor scenarios are permissible
under the language of § 271(a), and of course, the stat-
ute’s language controls. For example, it is true that at
common law the action of encouraging another to commit
a tort (traditional notions of inducement) makes you a
joint tortfeasor. And because such inducement is directly
and undisputedly covered by § 271(b), this common law
joint tortfeasor does not escape liability under § 271.
However, that particular joint tortfeasor scenario does not
likewise create liability under § 271(a) because the lan-
guage of § 271(a) precludes it. Section 271(a) in relevant
part says “whoever . . . uses . . . any patented invention.”
To be liable as a joint tortfeasor under § 271(a), all the
elements or steps of the claim must be performed, and
each accused joint tortfeasor must perform at least one of
the steps pursuant to some common purpose, design or
plan. If you perform none of the steps, you are not jointly
using the patented invention, and thus are not a joint
tortfeasor covered by § 271(a).
    Akamai, the patentee, is harmed identically whether
Limelight performed all of the method steps or whether
Limelight performed three and had its customer perform
the fourth. Under the majority’s reading of the statute,
the patentee has no redress for the harm if two people act
together to perform the patented method but does have
redress if that identical method is performed by a single
entity. It is difficult for me to conceive of how that guar-
antees the patentee’s right of exclusivity or compensates
the patentee when that right of exclusivity is clearly
violated. The majority claims that the dissent would
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   29



extend liability to independent arms-length actors who
just happen to collectively perform the claimed steps. Not
so. Concerted action pursuant to a common plan, pur-
pose, or design requires that “[p]arties are acting in
concert when they act in accordance with an agreement to
cooperate in a particular line of conduct or to accomplish a
particular result.” Restatement (Second) of Torts § 876,
cmt. a. Such concerted action has occurred in this case.
Limelight performed all but one step of that patented
method and its customers, pursuant to a contract for
Limelight’s services, performed the final step (tagging).
Limelight and those customers had an express agreement
that when Limelight’s content delivery system was used,
the customers would tag content and Limelight would
perform all the other steps—this is “an agreement to
cooperate in a particular line of conduct or to accomplish a
particular result.”
    I have not “blithely tossed [common law principles of
joint tortfeasor] aside.” Maj. at 23. The majority has
created a straw man and in folly beat it down. But joint
tortfeasor concerted action, according to a common plan,
purpose, or design, is not that straw man. My interpreta-
tion of the Patent Act embraces the common law tort
principles. There was liability for what Limelight did
here prior to the 1952 Patent Act, and the Patent Act
continues to give rise to liability for such infringement in
§ 271(a). I do not agree with the majority that Congress
intentionally sought to do away with such liability, and
the plain language of the statute does not comport with
such claims.
    The majority’s complaints about predatory customer
suits are a smokescreen. Maj. at 24. The only accused
infringer in this case is Limelight. We do not, and need
not, decide whether Limelight’s customers should be
30       AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.



liable, as none of those customers have been sued by
Akamai. 6
     The majority’s concern that joint tortfeasor liability
will cause a “drastic expansion of predatory customer
suits” is unwarranted. Maj. at 24. The majority’s dra-
matic rhetoric is meant to appeal to the frenzy over
“trolls.” Concerns about customer suits stem from the fact
that patentees might choose to sue less sophisticated
customers who lack the resources or incentive to defend
against the patent suit, while the manufacturers, who
generally have a greater interest and ability to defend
against the suit, cannot participate in the lawsuit. See,
e.g., Microsoft Corp. v. DataTern, Inc., 755 F.3d 899, 904–
907 (Fed. Cir. 2014) (prohibiting Microsoft’s declaratory
judgment action despite the fact that the patentee sued
over 100 customers).
    These concerns do not exist in the joint tortfeasor con-
text because if a customer were ever sued, the manufac-
turer can be joined voluntarily (or even involuntarily).
Where it is the combined actions of the customer and
manufacturer pursuant to a common plan that give rise to
liability, if the customer is sued, the manufacturer can




     6  While not deciding whether Limelight’s customers
could be liable, the Supreme Court has stated that “[t]he
right to use is a comprehensive term and embraces within
its meaning the right to put into service any given inven-
tion.” Bauer, 229 U.S. at 10–11. And we note that a
system claim is infringed by an end-user when “the sys-
tem is put into service,” regardless of whether the end-
user possesses or made the system. Centillion Data Sys.,
LLC v. Qwest Commc’ns Int’l, Inc., 631 F.3d 1279, 1284–
85 (Fed. Cir. 2011); NTP, 418 F.3d at 1317.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.     31



join and defend against the suit. 7 Once joined, the manu-
facturer could secure a judgment that would resolve suits
as against all its customers. If the manufacturer secures
a judgment against the patentee, the patentee could be
collaterally estopped from bringing any other customer
suits. If the patentee is successful against the manufac-
turer and recovers damages, it cannot separately recover
damages from the customers who use that product.
Glenayre Elecs., Inc. v. Jackson, 443 F.3d 851, 864 (Fed.
Cir. 2006) (“[A] party is precluded from suing to collect
damages for direct infringement by a buyer and user of a
product when actual damages covering that very use have
already been collected from the maker and seller of that
product.”). The law is clear: if the patentee recovers
damages from Limelight here, it cannot later recover
damages from any customers of Limelight; there is no
double dipping.
     Finally, to do either what the majority proposes or
what I propose requires en banc action, as it is admittedly
at odds with binding precedent. Despite mentioning the
joint enterprise standard twelve times in the opinion and
concluding that the collaborative actions of Limelight and
its customers do not give rise to joint enterprise liability, 8


    7   And if a customer were found liable (such as
Limelight’s content provider customers), that customer
would only be jointly and severally liable for the single act
of infringement that it performed in concert with Lime-
light. Only the manufacturer, Limelight, is liable for the
harm caused by all of the uses of its software.
    8   It is troubling that the majority articulates a new
standard for liability, joint enterprise, which is in conflict
with our prior precedent and then decides this factual
question on appeal, with no opportunity for briefing,
argument, or record development by the parties. “Wheth-
er [the joint enterprise] elements exist is frequently a
32   AKAMAI TECHNOLOGIES, INC.    v. LIMELIGHT NETWORKS, INC.



the Majority claims that it is not adopting joint enterprise
liability. It is not, and cannot adopt the joint enterprise
standard, because one panel cannot overrule a prior panel
decision. Our opinion in Golden Hour Data Systems, Inc.
v. emsCharts, Inc., 614 F.3d 1367, 1371, 1380–81 (Fed.
Cir. 2010) found no liability where two defendants
“formed a strategic partnership, enabled their two pro-
grams to work together, and collaborated to sell the two
programs as a unit” that practiced all of the claimed
method steps. The jury had found infringement under the
direction or control test in Golden Hour, our court held
that those circumstances, the very same ones that would
qualify for joint enterprise, do not give rise to liability. Id.
at 1381. And Judge Linn’s dissent in Akamai, which was
joined by Judge Prost, correctly explained: “Because the
parties in [Golden Hour] would have satisfied the test for
joint enterprise based on common purpose and an equal
right of mutual control, . . . the en banc court should
expressly overrule the holding in that case.” Akamai, 692
F.3d at 1349 (Linn, J., dissenting).
                           *****
    Congress codified existing common law joint tortfea-
sor principles in §§ 271(a), (b), and (c). Section 271(a)
covers direct infringement, which occurs when all the
steps of the method are performed either by a single
entity or multiple entities acting in concert or collabora-
tion, jointly, or under direction or control. This does not
extend to arms-length actors who unwittingly perform a
single step—there must be concerted action to achieve a
common goal. The plain language of § 271(a), and in
particular Congress’ decision to make liable “whoever . . .
uses . . . any patented invention,” expressly includes joint



question of fact for the jury.”     Restatement (Second) of
Torts § 491, cmt. c.
AKAMAI TECHNOLOGIES, INC.   v. LIMELIGHT NETWORKS, INC.   33



tortfeasor concerted action. To conclude otherwise ren-
ders the statute’s use of the word “whoever” internally
inconsistent. There is no question that §§ 101, 161, and
171, which state “whoever invents,” includes the concert-
ed action of multiple inventors each playing a part in the
conception of the patented invention. Likewise “whoever
uses” includes the concerted action of multiple parties
each playing a part in using the patented process. The
majority’s single entity rule is judicial fiction which
upsets the settled expectations of the inventing and
business community. I respectfully dissent from the
majority’s construction which is inconsistent with the
plain language of the statute, renders the statute inter-
nally inconsistent, and creates a gaping hole in infringe-
ment which no one even attempts to justify.
