United States Court of Appeals
           For the Eighth Circuit
       ___________________________

               No. 16-3976
       ___________________________

            United States of America

      lllllllllllllllllllll Plaintiff - Appellant

                          v.

              Steven Shane Horton

     lllllllllllllllllllll Defendant - Appellee

            ------------------------------

        Electronic Frontier Foundation

lllllllllllllllllllllAmicus on Behalf of Appellee(s)
         ___________________________

               No. 16-3982
       ___________________________

            United States of America

      lllllllllllllllllllll Plaintiff - Appellant

                          v.

             Beau Brandon Croghan

     lllllllllllllllllllll Defendant - Appellee

            ------------------------------
                          Electronic Frontier Foundation

                  lllllllllllllllllllllAmicus on Behalf of Appellee(s)
                                        ____________

                     Appeals from United States District Court
                 for the Southern District of Iowa - Council Bluffs
                                  ____________

                              Submitted: April 6, 2017
                                Filed: July 24, 2017
                                  ____________

Before SMITH, Chief Judge, SHEPHERD, Circuit Judge, and FENNER, District
Judge.1
                              ____________

SMITH, Chief Judge.

      Steven Horton and Beau Croghan were indicted separately for accessing child
pornography in violation of 18 U.S.C. § 2252A(a)(5)(B). Both men moved to
suppress evidence obtained through a warrant authorizing a search of their respective
computers through the use of a Network Investigative Technique (NIT). In a
combined order, the district court granted suppression. The government appeals
pursuant to 18 U.S.C. § 3731. We reverse.

                                 I. Background
       The Onion Router (“Tor”) network exists to provide anonymity to Internet
users by masking user data, hiding information by funneling it through a series of
interconnected computers. The Tor Project, a not-for-profit research organization in

      1
       The Honorable Gary A. Fenner, United States District Judge for the Western
District of Missouri, sitting by designation.

                                          -2-
Massachusetts, provides free downloads of the Tor program on its website. Although
Tor’s intended users include whistleblowers, journalists, law enforcement personnel,
activists, and privacy-minded consumers, users with more nefarious motives have
used Tor’s anonymity capabilities for criminal purposes.

       In September 2014, the FBI began investigating an internet forum for sharing
child pornography hosted on the Tor network called “Playpen.” Accessible through
a web address of seemingly random letters and numbers, users entered Playpen by
creating a username and password. Playpen had more than 150,000 registered
accounts. In January 2015, FBI agents gained access to Playpen servers and relocated
the website content to servers in a secure government facility in the Eastern District
of Virginia. The agents assumed administrative control of the site. Although FBI
investigators could monitor Playpen traffic, users were still cloaked by the Tor
encryption technology.

       On February 20, 2015, FBI Special Agent Douglas Macfarlane, a 19-year
veteran of the agency, applied for a warrant in the Eastern District of Virginia to
search computers that accessed Playpen. The warrant described the application of the
NIT, which sent computer code to Playpen users’ computers that instructed the
computers to transmit certain information back to the government. The information
sent back included the computer’s Internet Protocol (IP) address, operating system
information, operating system username, and its Media Access Control (MAC)
address, which is a unique number assigned to each network modem. Although
Playpen was hosted in the Eastern District of Virginia, the warrant explained that “the
NIT may cause [a defendant’s] computer—wherever located—to send to a computer
controlled by or known to the government, network level messages containing
information that may assist in identifying the computer.” A United States magistrate
judge signed the warrant, and the FBI began collecting the personal data of Playpen
users.



                                         -3-
        During the warrant period, Horton accessed Playpen with the username
“boybuttlover123.” The FBI located Horton in the Southern District of Iowa through
information obtained by the NIT. Horton was arrested and charged in Iowa. Croghan
also accessed Playpen during the relevant time period, using the username
“beau2358.” Through the NIT, law enforcement located his home in Iowa, executed
a search of his home, and indicted him. Both Horton and Croghan moved to suppress
evidence obtained through the NIT. In a combined order, the district court found that
the magistrate judge exceeded her statutory authority by issuing the NIT warrant
beyond the district court’s jurisdictional boundaries. See Fed. R. Crim. P. 41(b). The
district court noted that “a warrant issued without proper jurisdiction is void ab initio
and . . . any search conducted pursuant to such warrant is the equivalent of a
warrantless search.” United States v. Croghan, 209 F. Supp. 3d 1080, 1090 (S.D.
Iowa 2016). The district court suppressed the evidence obtained through the warrant.
Id. at 1091.

       This single NIT warrant executed in Virginia has implicated more than a
hundred defendants across the United States. More than 40 district courts have held
hearings regarding suppression of evidence generated from the NIT, including several
courts in this circuit. See, e.g., United States v. Dzwonczyk, No. 4:15-CR-3134, 2016
WL 7428390 (D. Neb. Dec. 23, 2016); United States v. Johnson, No.
15-00340-01-CR-W-GAF, 2016 WL 6136586 (W.D. Mo. Oct. 20, 2016); United
States v. Jean, 207 F. Supp. 3d 920 (W.D. Ark. 2016); see also United States v.
Taylor, No. 2:16-CR-00203-KOB-JEO-1, 2017 WL 1437511, at *3–4 (N.D. Ala. Apr.
24, 2017) (collecting cases). Most district courts that have addressed these
suppression motions have denied them, but they have taken varying approaches in
reaching that result. See Dzwonczyk, 2016 WL 7428390, at *4 (“[T]he Court takes a
different path to this [non-suppression] result.”). Only a few have granted
suppression, and all used similar reasoning. See, e.g., United States v. Workman, 205
F. Supp. 3d 1256 (D. Colo. 2016); United States v. Levin, 186 F. Supp. 3d 26
(D. Mass. 2016); United States v. Arterbury, No. 15-CR-182-JHP, 2016 U.S. Dist.

                                          -4-
LEXIS 67091 (N.D. Okla. Apr. 25, 2016), adopted by No. 15–CR–182–JHP, 2016
U.S. Dist. LEXIS 67092 (N.D. Okla. May 17, 2016).

                                     II. Discussion
      “On appeal from a grant of a motion to suppress, we review a district court’s
findings of fact for clear error and its legal conclusions de novo.” United States v.
Marasco, 487 F.3d 543, 547 (8th Cir. 2007). We will affirm the district court’s
decision “unless it is not supported by substantial evidence on the record; it reflects
an erroneous view of the applicable law; or upon review of the entire record, the
appellate court is left with the definite and firm conviction that a mistake has been
made.” United States v. Layne, 973 F.2d 1417, 1420 (8th Cir. 1992). This appeal
challenges the lower court’s legal conclusions, so our review is de novo.

                             A. The Fourth Amendment
      The right of the people to be secure in their persons, houses, papers, and
      effects, against unreasonable searches and seizures, shall not be violated,
      and no Warrants shall issue, but upon probable cause, supported by Oath
      or affirmation, and particularly describing the place to be searched, and
      the persons or things to be seized.

U.S. Const. amend. IV. “[W]hat [a citizen] seeks to preserve as private, even in an
area accessible to the public, may be constitutionally protected.” Katz v. United
States, 389 U.S. 347, 351 (1967). “The fact that the electronic device employed to
achieve [the search] did not happen to penetrate the [defendant’s physical space] can
have no constitutional significance.” See id. at 353.

       We first address whether a warrant was required for the use of a NIT. At least
one district court in this circuit has determined that a warrant would likely be
unnecessary for an NIT that exclusively searched for IP addresses, relying on a line
of cases allowing third-party subpoenas of the same. See Jean, 207 F. Supp. 3d at 933
(“IP addresses are unlikely to be entitled to the same Fourth Amendment protections

                                         -5-
as are the substantive contents of users’ computers.”). A defendant’s publicly
available information may not be entitled to Fourth Amendment protection. See Katz,
389 U.S. at 351 (“What a person knowingly exposes to the public, even in his own
home or office, is not a subject of Fourth Amendment protection.”). But, “[t]he
government is not permitted to conduct a warrantless search of a place in which a
defendant has a reasonable expectation of privacy simply because it intends to seize
property for which the defendant does not have a reasonable expectation of privacy.”
Workman, 205 F. Supp. 3d at 1265.

       This case differs from cases in which an IP address is voluntarily provided to
third parties. See United States v. Christie, 624 F.3d 558, 573 (3d Cir. 2010) (“Federal
courts have uniformly held that ‘subscriber information provided to an internet
provider is not protected by the Fourth Amendment’s privacy expectation’ because
it is voluntarily conveyed to third parties.” (quoting United States v. Perrine, 518
F.3d 1196, 1204 (10th Cir. 2008))). In this case, the FBI sent computer code to the
defendants’ respective computers that searched those computers for specific
information and sent that information back to law enforcement. Even if a defendant
has no reasonable expectation of privacy in his IP address, he has a reasonable
expectation of privacy in the contents of his personal computer. See United States v.
Turner, 839 F.3d 429, 434 (5th Cir. 2016) (saying “a privacy interest exists in the
electronic contents of computers and cell phones”). Moreover, the NIT retrieved
content from the defendants’ computers beyond their IP addresses. We conclude the
execution of the NIT in this case required a warrant. “Our answer to the question of
what police must do before searching a [computerized device] . . . is accordingly
simple—get a warrant.” Riley v. California, 134 S. Ct. 2473, 2495 (2014).

                             B. Magistrate Jurisdiction
       Congress provided judicial authority to United States magistrate judges “within
the district in which sessions are held by the court that appointed the magistrate
judge . . . and elsewhere as authorized by law.” 28 U.S.C. § 636(a). This authority

                                          -6-
may be modified by the Rules of Criminal Procedure. Id. § 636(a)(1). When the NIT
warrant was issued in this case, Federal Rule of Criminal Procedure 41 authorized a
magistrate judge “to issue a warrant to search for and seize a person or property
located within the district.” Fed. R. Crim. P. 41(b)(1). The Rule provided exceptions
to this jurisdictional limitation for property moved outside of the jurisdiction, for
domestic and international terrorism, for the installation of a tracking device, and for
property located outside of a federal district. See id.2 None of these exceptions
expressly allow a magistrate judge in one jurisdiction to authorize the search of a
computer in a different jurisdiction.

       The government argues that the tracking-device exception in Rule 41(b)(4)
should apply here. This exception authorizes the magistrate judge “to issue a warrant
to install within the district a tracking device,” see id., using “an electronic or
mechanical device which permits the tracking of the movement of a person or object,”
18 U.S.C. § 3117(b). The government argues that the defendants made a “virtual” trip


      2
       On December 1, 2016, Federal Rule of Criminal Procedure 41(b)(6) was added
to provide an additional exception to the magistrate’s jurisdictional limitation by
allowing warrants for programs like the NIT:

      a magistrate judge with authority in any district where activities related
      to a crime may have occurred has authority to issue a warrant to use
      remote access to search electronic storage media and to seize or copy
      electronically stored information located within or outside that district
      if:

             (A) the district where the media or information is located has
             been concealed through technological means; or

             (B) in an investigation of a violation of 18 U.S.C. § 1030(a)(5),
             the media are protected computers that have been damaged
             without authorization and are located in five or more districts.


                                          -7-
to the Eastern District of Virginia to access child pornography and that investigators
“installed” the NIT within that district. Although plausible, this argument is belied
by how the NIT actually worked: it was installed on the defendants’ computers in
their homes in Iowa. The government rightly points out that our court interprets
Rule 41 flexibly in light of advances in technology, see United States v. N.Y. Tel. Co.,
434 U.S. 159, 169 (1977); United States v. Falls, 34 F.3d 674, 678–79 (8th Cir.
1994), but we agree with the district court that the “virtual trip” fiction “stretches the
rule too far,” Croghan, 209 F. Supp. 3d at 1088 (quoting United States v. Michaud,
No. 3:15-CR-05351-RJB, 2016 WL 337263, at *6 (W.D. Wash. Jan. 28, 2016)). We
agree with the majority of courts that have reviewed the NIT warrant. These courts
have concluded that “the plain language of Rule 41 and the statutory definition of
‘tracking device’ do not . . . support so broad a reading as to encompass the
mechanism of the NIT used in this case.” Id. Thus, we hold that the NIT warrant
exceeded the magistrate judge’s jurisdiction.

                                 C. Rule 41 Violation
       Once we have determined that Rule 41 has been violated, we next consider
whether the violation was merely technical or instead rises to the level of a violation
of the Fourth Amendment. United States v. Krueger, 809 F.3d 1109, 1113 (10th Cir.
2015); United States v. Moore, 41 F.3d 370, 375 (8th Cir. 1994) (analyzing whether
a warrant defect was substantive or “a mere technical” error). A Rule 41 violation “is
not per se an unreasonable search and seizure in violation of the Fourth Amendment.”
United States v. Welch, 811 F.3d 275, 280 (8th Cir.), cert. denied, 136 S. Ct.
2476 (2016). “Absent a constitutional infirmity, the exclusionary rule is applied only
to violations of Federal Rule 41 that prejudice a defendant or show reckless disregard
of proper procedure.” United States v. Hyten, 5 F.3d 1154, 1157 (8th Cir. 1993).
Thus, we need not address prejudice or reckless disregard for procedure if we
determine that a warrant issued outside of a magistrate’s jurisdictional boundaries is
a violation of constitutional magnitude—that is, a violation of the Fourth
Amendment.

                                           -8-
      On this question, the district court determined that “because ‘the magistrate
judge lacked authority, and thus jurisdiction, to issue the NIT Warrant, there simply
was no judicial approval’ of the NIT Warrant as required by the Fourth Amendment.”
Croghan, 209 F. Supp. 3d at 1090 (quoting Levin, 186 F. Supp. 3d at 36). The court
“adopt[ed] the well-reasoned decisions in Levin and Arterbury and conclude[d] that
a warrant issued without proper jurisdiction is void ab initio and that any search
conducted pursuant to such warrant is the equivalent of a warrantless search.” Id.
Most district courts have determined that the Rule 41 violation here does not violate
the Constitution. Our sister circuits, however, have concluded otherwise.

       In United States v. Glover, the D.C. Circuit rejected a warrant that authorized
the installation of an audio recording device in a defendant’s vehicle, “regardless of
whether the vehicle was located in the District of Columbia, District of Maryland, or
the Eastern District of Virginia.” 736 F.3d 509, 510 (D.C. Cir. 2013). Relevant to this
case, the court held that the warrant “appears, on its face, to be in violation” of
Rule 41. Id. at 515. “Even if we assume that an imperfect authorizing order could be
thought facially sufficient, we do not see how a blatant disregard of a district judge’s
jurisdictional limitation can be regarded as only ‘technical.’” Id. The court reversed
the lower court and ordered a new trial, suppressing the evidence obtained from the
“facially insufficient” warrant. Id. at 510.

       In United States v. Krueger, the Tenth Circuit determined that a similar Rule 41
violation prejudiced the defendant, without reaching the constitutional question of
magistrate jurisdiction. 809 F.3d at 1116–17. Then-Judge Gorsuch explained
separately in a concurrence that he believed jurisdictional errors under Rule 41 were
errors of constitutional magnitude:

      For looking to the common law at the time of the framing it becomes
      quickly obvious that a warrant issued for a search or seizure beyond the
      territorial jurisdiction of a magistrate’s powers under positive law was


                                          -9-
      treated as no warrant at all—as ultra vires and void ab initio to use some
      of the law’s favorite Latin phrases—as null and void without regard to
      potential questions of “harmlessness” (such as, say, whether another
      judge in the appropriate jurisdiction would have issued the same warrant
      if asked). . . . The principle animating the common law at the time of the
      Fourth Amendment’s framing was clear: a warrant may travel only so far
      as the power of its issuing official. And that principle seems clearly
      applicable—and dispositive—here.

Id. at 1123–24 (Gorsuch, J., concurring).

       The district court followed this logic, finding the NIT warrant invalid at its
inception and therefore the constitutional equivalent of a warrantless search.
Croghan, 209 F. Supp. 3d at 1090–91; see also Taylor, 2017 WL 1437511, at *14
(“[T]he Fourth Amendment does not impose a venue requirement . . . . But inherent
in the notion of a ‘neutral, detached magistrate’ is that the magistrate have authority
to issue the warrant.” (citation omitted)). In response, the government argues that
because the NIT warrant was proper in the Eastern District of Virginia, it cannot be
wholly void or void ab initio. See United States v. Ryan Anthony Adams, No.
6:16-CR-11-ORL-40GJK, 2016 WL 4212079, at *6 (M.D. Fla. Aug. 10, 2016) (“The
Court finds that the magistrate judge in the Eastern District of Virginia had the
authority to issue search warrants—that is, the inherent power to do so.”). The
possibility that the magistrate could have executed a proper warrant in the Eastern
District of Virginia, however, does not save this warrant from its jurisdictional error.
See Glover, 736 F.3d at 510 (rejecting a warrant for multiple jurisdictions including
the magistrate’s proper district); United States v. Master, 614 F.3d 236, 241 (6th Cir.
2010) (rejecting a warrant issued by a magistrate with warrant-issuing authority in a
neighboring county); see also Krueger, 809 F.3d at 1116 (rejecting the argument of
warrant validity “so long as the Government hypothetically could have obtained the
warrant from a different federal magistrate judge with warrant-issuing authority under



                                         -10-
the Rule”). We agree with the district court and find that the NIT warrant was void
ab initio, rising to the level of a constitutional infirmity.3

                              D. Good-Faith Exception
       “The fact that a Fourth Amendment violation occurred—i.e., that a search or
arrest was unreasonable—does not necessarily mean that the exclusionary rule
applies.” Herring v. United States, 555 U.S. 135, 140 (2009). “Even when an
unreasonable search does exist, the Supreme Court has explained, we must be
persuaded that ‘appreciable deterrence’ of police misconduct can be had before
choosing suppression as the right remedy for a Fourth Amendment violation.”
Krueger, 809 F.3d at 1125 (Gorsuch, J., concurring) (quoting Herring, 555 U.S. at
141). A warrantless search is “presumptively unreasonable and suppression is an
appropriate remedy unless the Leon good faith exception applies.” Croghan, 209 F.
Supp. 3d at 1090–91; see United States v. Leon, 468 U.S. 897 (1984). We review the
application of the Leon exception de novo. United States v. Houston, 665 F.3d 991,
994 (8th Cir. 2012).

       “The Fourth Amendment contains no provision expressly precluding the use
of evidence obtained in violation of its commands, and an examination of its origin
and purposes makes clear that the use of fruits of a past unlawful search or seizure
‘work[s] no new Fourth Amendment wrong.’” Leon, 468 U.S. at 906 (alteration in
original) (quoting United States v. Calandra, 414 U.S. 338, 354 (1974)). In Leon, the
Supreme Court determined that “the marginal or nonexistent benefits produced by
suppressing evidence obtained in objectively reasonable reliance on a subsequently
invalidated search warrant cannot justify the substantial costs of exclusion.” Id.
at 922. In analyzing this good-faith exception in the context of the NIT warrant, the

      3
       The defendants and Amicus Curiae argue that the NIT warrant failed to meet
the Fourth Amendment’s particularity requirement. Because we find that the NIT
warrant failed to meet constitutional standards on alternative grounds, we decline to
address this issue.

                                        -11-
district court determined “that Leon is inapplicable to issuance of the NIT Warrant
because the NIT Warrant was issued without jurisdiction and was, therefore, void ab
initio.” Croghan, 209 F. Supp. 3d at 1091. In making this determination, the district
court relied heavily on the reasoning in Levin:

      To hold that the good-faith exception is applicable here would collapse
      the distinction between a voidable and a void warrant. But this
      distinction is meaningful: the former involves “judicial error,” such as
      “misjudging the sufficiency of the evidence or the warrant application’s
      fulfillment of the statutory requirements[,]” while the latter involves
      “judicial authority,” i.e., a judge “act[ing] outside of the law, outside of
      the authority granted to judges in the first place.”

Levin, 186 F. Supp. 3d at 41 (alterations in original) (quoting State v. Hess, 770
N.W.2d 769, 776 (Wis. Ct. App. 2009)). The government argues that this distinction
between “voidable” and “void” warrants is untenable in the good-faith exception
context, and we agree.

       In Master, the Sixth Circuit analyzed a case in which a state judge issued a
warrant for a search outside of his jurisdictional boundaries that he “had no authority
to issue.” 614 F.3d at 241. The court expressly rejected an argument that when a
judge “lack[s] legal authority to issue the relevant warrant, the good faith exception
is foreclosed.” Id. Because of intervening Supreme Court precedent, the court
abrogated a previous holding in which the court did not apply the Leon exception to
a warrant void ab initio. See id. at 241–43 (overruling in part United States v. Scott,
260 F.3d 512 (6th Cir. 2001)). “Arguably, the issuing magistrate’s lack of authority
has no impact on police misconduct . . . .” Id. at 242. Our review of relevant Supreme
Court precedent leads us to a similar conclusion: that the Leon exception can apply
to warrants void ab initio like this one.




                                         -12-
       In Leon, the Supreme Court noted that “[p]enalizing the officer for the
magistrate’s error, rather than his own, cannot logically contribute to the deterrence
of Fourth Amendment violations.” 468 U.S. at 921. The Court has applied the Leon
exception in a strikingly wide array of cases. See, e.g., Davis v. United States, 564
U.S. 229 (2011) (binding precedent overruled); Herring, 555 U.S. 135 (recalled
warrant); Hudson v. Michigan, 547 U.S. 586 (2006) (knock-and-announce violation);
Arizona v. Evans, 514 U.S. 1 (1995) (outdated arrest warrant); Illinois v. Krull, 480
U.S. 340 (1987) (reliance on an unconstitutional statute). In all these cases, the Court
has not focused on the type of Fourth Amendment violation at issue, but rather
confined the “‘good-faith inquiry . . . to the objectively ascertainable question
whether a reasonably well trained officer would have known that the search was
illegal’ in light of ‘all of the circumstances.’” Herring, 555 U.S. at 145 (quoting Leon,
468 U.S. at 922 n.23). “As laid out in our cases, the exclusionary rule serves to deter
deliberate, reckless, or grossly negligent conduct, or in some circumstances recurring
or systemic negligence.” Id. at 144. We agree with the Sixth Circuit that regardless
of the type of warrant at issue that “[t]he Supreme Court has effectively created a
balancing test by requiring that in order for a court to suppress evidence following the
finding of a Fourth Amendment violation, ‘the benefits of deterrence must outweigh
the costs.’” Master, 614 F.3d at 243 (quoting Herring, 555 U.S. at 141).

        Having determined that the Leon exception may apply to a warrant void ab
initio, the question remains whether it should apply here. “To trigger the exclusionary
rule, police conduct must be sufficiently deliberate that exclusion can meaningfully
deter it, and sufficiently culpable that such deterrence is worth the price paid by the
justice system.” Herring, 555 U.S. at 144. “As with any remedial device, the rule’s
application has been restricted to those instances where its remedial objectives are
thought most efficaciously served.” Arizona, 514 U.S. at 11. “Suppression of
evidence . . . has always been our last resort, not our first impulse.” Hudson, 547 U.S.
at 591. In this case, the district court found that because “law enforcement was
sufficiently experienced, and that there existed adequate case law casting doubt on

                                          -13-
magisterial authority to issue precisely this type of NIT Warrant . . . the good faith
exception is inapplicable.” Croghan, 209 F. Supp. 3d at 1093. We disagree.

      Because Leon provides an exception for good faith, we apply it as long as the
circumstances do not demonstrate bad faith, such as:

      (1) when the affidavit or testimony supporting the warrant contained a
      false statement made knowingly and intentionally or with reckless
      disregard for its truth, thus misleading the issuing judge; (2) when the
      issuing judge “wholly abandoned his judicial role” in issuing the
      warrant; (3) when the affidavit in support of the warrant is “so lacking
      in indicia of probable cause as to render official belief in its existence
      entirely unreasonable”; and (4) when the warrant is “so facially
      deficient” that no police officer could reasonably presume the warrant
      to be valid.

Houston, 665 F.3d at 995 (quoting United States v. Proell, 485 F.3d 427, 431 (8th
Cir. 2007)).

       The defendants argue that the NIT warrant demonstrates such bad faith. The
defendants argue that the NIT warrant affidavit exhibited a reckless disregard for its
truth by listing the Eastern District of Virginia as the place to be searched, when law
enforcement knew that computers could be searched anywhere in the country. At least
one court has agreed with this reasoning. See Workman, 205 F. Supp. 3d at 1264 (“In
my view, had [the magistrate judge] understood that the NIT technology would search
computers in other districts—rather than track information as it traveled from her
district to others—she probably would not have issued the NIT Warrant given the
limitations of the Rule.”). The warrant, however, discusses at length the NIT and how
it would be used to connect to computers “wherever located.” Even if it were
misleading to label the place to be searched as the Eastern District of Virginia, a
reasonable reader would have understood that the search would extend beyond the


                                         -14-
boundaries of the district because of the thorough explanation provided in the
attached affidavit. This does not amount to a reckless disregard for the truth.

       The defendants also argue that the NIT warrant was facially deficient because
FBI agents should have known that a warrant purporting to authorize thousands of
searches throughout the country could not be valid. Specifically, Horton argues that
“there can be no credible argument that officers reasonably believed that none of the
214,898 members of [Playpen] were located outside of Virginia.” E.g., In re Warrant
to Search a Target Compt. at Premises Unknown, 958 F. Supp. 2d 753 (S.D. Tex.
2013) (finding a similar warrant that exceeded the territorial limits of Rule 41
invalid). We, however, will not find an obvious deficiency in a warrant that a number
of district courts have ruled to be facially valid. See, e.g., Johnson, 2016 WL
6136586, at *5; Jean, 207 F. Supp. 3d at 943. Further, we have declined to impose
an obligation on law enforcement to “know the legal and jurisdictional limits of a
judge’s power to issue interstate search warrants.” Houston, 665 F.3d at 996. Law
enforcement did not demonstrate bad faith, and we will apply the Leon balancing test
as instructed by the Supreme Court.4

       “For exclusion to be appropriate, the deterrence benefits of suppression must
outweigh its heavy costs.” Davis, 564 U.S. at 237. Because Rule 41 has been updated
to authorize warrants exactly like this one, there is no need to deter law enforcement
from seeking similar warrants. As noted above, we do not believe that law
enforcement acted in bad faith, and “[e]xclusion of the evidence seized pursuant to
the NIT warrant would serve little deterrent purpose where the mistaken conduct of
the magistrate judge, not the officers, invalidated the warrant.” Taylor, 2017 WL
1437511, at *16. And the costs of exclusion in this case are substantial. Suppression

      4
        Additionally, the defendants argue that the FBI’s sting operation itself was
unreasonable, but this issue has no bearing on whether law enforcement acted
reasonably by obtaining and relying on the NIT warrant. Thus, we will not address
this issue.

                                        -15-
here would extend beyond the present defendants and impact multiple cases within
this circuit. On balance, the marginal benefit of deterrence fails to outweigh the
associated costs: “letting guilty and possibly dangerous defendants go
free—something that ‘offends basic concepts of the criminal justice system.’”
Herring, 555 U.S. at 141 (quoting Leon, 468 U.S. at 908). We therefore apply the
Leon exception to this case and reverse the district court’s grant of suppression.

                                  III. Conclusion
     Accordingly, we reverse the district court’s order suppressing the evidence and
remand these cases for further proceedings.

FENNER, District Judge, concurring in part and dissenting in part.

       I respectfully dissent from Parts II.B and II.C of the court’s opinion. Under
Federal Rule of Criminal Procedure 41(b)(4), a magistrate judge is authorized to issue
a warrant to install a tracking device within the magistrate’s district regardless of
whether the movement of the person or property being tracked moves outside of the
district. Fed. R. Crim. P. 41(b)(4). As the majority acknowledged, Rule 41 is
interpreted with flexibility in light of advances of technology. See United States v.
New York Tel. Co., 434 U.S. 159 (1977); United States v. Falls, 34 F.3d 674 (8th Cir.
1994). I believe the “installation” of the tracking device occurred where law
enforcement attached the NIT to the flow of information, i.e. the Eastern District of
Virginia. See United States v. Jean, 207 F. Supp. 3d 920, 942-43 (W.D. Ark. 2016)
(reasoning that installation occurred in the Eastern District of Virginia because the
NIT was designed to track the flow of intangible property and law enforcement did
not leave the jurisdiction to attach the NIT to the defendant’s computer). Given the
flexibility with which Rule 41 is interpreted and the facts of this case, I would
conclude that Rule 41 does encompass the NIT warrant and find no violation of Rule
41. I concur in the court’s opinion in all other respects.
                         _____________________________

                                        -16-
