                   FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                    No. 05-50092
               Plaintiff-Appellant,
                                                D.C. No.
               v.
                                           CR-04-00199-TJH-
CHRISTOPHER LEE ADJANI; JANA                       01
REINHOLD,
                                               OPINION
            Defendants-Appellees.
                                       
        Appeal from the United States District Court
            for the Central District of California
       Terry J. Hatter, Chief District Judge, Presiding

                   Argued and Submitted
           January 13, 2006—Pasadena, California

                      Filed July 11, 2006

          Before: Mary M. Schroeder, Chief Judge,
        Daniel M. Friedman* and Raymond C. Fisher,
                       Circuit Judges.

                   Opinion by Judge Fisher




  *The Honorable Daniel M. Friedman, Senior United States Circuit
Judge for the Federal Circuit, sitting by designation.

                              7577
                   UNITED STATES v. ADJANI                7581


                         COUNSEL

Elyssa Getreu, Assistant United States Attorney, Los Angeles,
California, for the plaintiff-appellant.

Marilyn E. Bednarski, Kaye, McLane & Bednarski, LLP, Pas-
adena, California, for defendant-appellee Jana Reinhold.


                         OPINION

FISHER, Circuit Judge:

   While executing a search warrant at the home of defendant
Christopher Adjani to obtain evidence of his alleged extor-
tion, agents from the Federal Bureau of Investigation seized
Adjani’s computer and external storage devices, which were
later searched at an FBI computer lab. They also seized and
subsequently searched a computer belonging to defendant
Jana Reinhold, who lived with Adjani, even though she had
not at that point been identified as a suspect and was not
named as a target in the warrant. Some of the emails found
on Reinhold’s computer chronicled conversations between her
and Adjani that implicated her in the extortion plot. Relying
in part on the incriminating emails, the government charged
both Adjani and Reinhold with conspiring to commit extor-
tion in violation of 18 U.S.C. § 371 and transmitting a threat-
ening communication with intent to extort in violation of 18
U.S.C. § 875(d).

  The defendants brought motions to suppress the emails,
arguing that the warrant did not authorize the seizure and
search of Reinhold’s computer and its contents; but if it did,
7582                    UNITED STATES v. ADJANI
the warrant was unconstitutionally overbroad or, alternatively,
the emails fell outside the scope of the warrant. The district
court granted the defendants’ motion to suppress the email
communications between Reinhold and Adjani, finding that
the agents did not have sufficient probable cause to search
Reinhold’s computer, and that once they discovered informa-
tion incriminating her, the agents should have obtained an
additional search warrant. The government appeals this evi-
dentiary ruling, but only with respect to three emails dated
January 12, 2004.

   The district court’s ruling on the motion to suppress is sub-
ject to de novo review. United States v. Vargas-Castillo, 329
F.3d 715, 722 (9th Cir. 2003). We review de novo a district
court’s determination regarding the specificity of a warrant,
including whether it is overbroad or not sufficiently particu-
lar. United States v. Wong, 334 F.3d 831, 836-37 (9th Cir.
2003). We hold that the government had probable cause to
search Reinhold’s computer, the warrant satisfied our test for
specificity and the seized e-mail communications fell within
the scope of the properly issued warrant.1 Accordingly, we
reverse the district court’s order suppressing the January 12,
2004 email communications between Reinhold and Adjani.

                           I.   Background

A.     The Extortion Scheme2
   1
     The FBI agents engaged in multiple searches and seizures here. First,
FBI agents searched Adjani’s residence. During the course of this search,
the agents seized Reinhold’s and Adjani’s computers. Then, at the FBI
computer lab, agents searched Reinhold’s computer for evidence of the
alleged extortion. Finally, the agents seized the three e-mails forming the
basis of this appeal. For purposes of our analysis, however, we collapse
the first three events into one, generally referring to it as the “search” of
Reinhold’s computer. As for the last event, we refer to it as the “seizure”
of e-mail communications.
   2
     The following factual summary is based entirely on the FBI affidavit
presented to, and relied upon by, the magistrate judge in support of the
FBI’s request for an arrest warrant for Adjani and a search warrant for var-
ious premises.
                    UNITED STATES v. ADJANI                 7583
   Adjani was once employed by Paycom Billing Services
Inc. (formerly Epoch), which facilitates payments from Inter-
net users to its client websites. As a payment facilitator, Pay-
com receives and stores vast amounts of data containing
credit card information. On January 8, 2004, a woman (later
identified as Reinhold) delivered envelopes to three Paycom
partners, Christopher Mallick, Clay Andrews and Joel Hall.
Each envelope contained a letter from Adjani advising that he
had purchased a copy of Paycom’s database containing its cli-
ents’ sensitive financial information. The letter threatened that
Adjani would sell the Paycom database and master client con-
trol list if he did not receive $3 million. To prove his threats
were real, Adjani included samples of the classified data. He
directed the Paycom partners to sign an enclosed agreement
attesting to the proposed quid pro quo and fax it back to him
by January 12. The letter included Adjani’s email address,
cadjani@mac.com, and a fax number. Agents later learned
that Adjani’s email address was billed to Reinhold’s account.

   Evidence suggested that Adjani left Los Angeles on Janu-
ary 9, 2004, and ultimately ended up in Zurich, Switzerland.
From Switzerland, Adjani sent an email on January 12 to Joel
Hall to confirm that Hall and the others had received the
envelopes. Adjani followed up on this email on January 13 by
instructing Hall to contact him through AOL/Mac iChat
instant messaging if he wanted to discuss the settlement
agreement. With the FBI monitoring, Hall conversed several
times with Adjani on the Internet and over the telephone. In
spite of Adjani’s insistence that he remain overseas, Hall con-
vinced him to come to Los Angeles on January 26 to pick up
$2.5 million in exchange for the database.

   Adjani returned to Los Angeles on January 22, under FBI
surveillance. Reinhold, driving in a car that the FBI had ear-
lier identified as Adjani’s, was observed leaving Adjani’s res-
idence in Venice, California, picking him up from the airport
and returning to his residence. The FBI also observed Rein-
7584                UNITED STATES v. ADJANI
hold using an Apple computer, the same brand of computer
Adjani used to email and chat with Paycom.

B.     Obtaining and Executing the Search Warrant

   On January 23, 2004, based on the facts recited above and
attested to in FBI Agent Cloney’s affidavit (which was
affixed to the warrant), a federal magistrate judge granted the
government an arrest warrant for Adjani and a search warrant
covering Adjani’s Venice residence, his vehicle, his person
and the residence of the individual who had stolen the confi-
dential information from Paycom. The warrant specifically
sought “evidence of violations of [18 U.S.C. § 875(d)]: Trans-
mitting Threatening Communications With Intent to Commit
Extortion.” Further, the warrant expressly authorized seizure
of:

     5g. Records, documents and materials containing
     Paycom’s or Epoch’s master client control docu-
     ments, Paycom’s or Epoch’s email database, or other
     company information relating to Paycom or Epoch.

     5h. Records, documents and materials which
     reflect communications with Christopher Mallick,
     Clay Andrews, Joel Hall or other employees or offi-
     cers of Paycom or Epoch.

     5i. Any and all evidence of travel, including hotel
     bills and receipts, gasoline receipts, plane tickets,
     bus tickets, train tickets, or any other documents
     related to travel from January 8, 2004 to the present.

     ....

     5k. Computer, hard drives, computer disks, CD’s,
     and other computer storage devices.

With respect to the computer search, the warrant prescribed
the process to be followed: “In searching the data, the com-
                    UNITED STATES v. ADJANI                7585
puter personnel will examine all of the data contained in the
computer equipment and storage devices to view their precise
contents and determine whether the data falls within the items
to be seized as set forth herein.” Additionally, it noted that
“[i]n order to search for data that is capable of being read or
intercepted by a computer, law enforcement personnel will
need to seize and search . . . . [a]ny computer equipment and
storage device capable of being used to commit, further, or
store evidence of the offense listed above.”

   On January 26, 2004, agents observed Reinhold driving
Adjani, in a car registered to him, to his meeting with Pay-
com. While Adjani went into a hotel, Reinhold slipped into
the backseat of his car, placing curtains over the windows. At
this point, agents proceeded to search Adjani’s car. That same
day, agents executed the search warrant for Adjani’s Venice
residence. There they found and seized various computers and
hard drives, including Reinhold’s computer, which were later
sent to an FBI computer lab to be searched. During that search
process, the hard drive from Reinhold’s computer revealed
certain email correspondence between Reinhold and Adjani,
implicating Reinhold in the extortion plot and supporting a
charge of conspiracy against both of them.

   The defendants successfully sought suppression of these
seized email communications in the district court. This appeal
requires us to determine whether the agents permissibly
searched Reinhold’s computer; whether the warrant satisfied
our specificity standards; and whether the emails seized fell
within the scope of the otherwise properly issued warrant.

                        II.   Analysis

A.   Probable Cause

   The government principally argues that contrary to the dis-
trict court’s finding and the defendants’ assertions, the search
warrant affidavit established probable cause to search all
7586                 UNITED STATES v. ADJANI
instrumentalities that might contain “evidence of violations
of” 18 U.S.C. § 875(d), including Reinhold’s computer and
emails. Reinhold counters that the affidavit may have gener-
ally established probable cause, but did not do so with respect
to her computer, because “[i]n the affidavit, Reinhold was not
labeled as a target, suspect, or co-conspirator.”

  1.   Probable cause to issue the warrant

   [1] “A search warrant . . . is issued upon a showing of prob-
able cause to believe that the legitimate object of a search is
located in a particular place, and therefore safeguards an indi-
vidual’s interest in the privacy of his home and possessions
against the unjustified intrusion of the police.” Steagald v.
United States, 451 U.S. 204, 213 (1981). As the Supreme
Court has explained, the “probable cause standard . . . is a
practical, nontechnical conception.” Illinois v. Gates, 462
U.S. 213, 231 (1983) (quoting Brinegar v. United States, 338
U.S. 160, 176 (1949)). Furthermore, “probable cause is a fluid
concept — turning on the assessment of probabilities in par-
ticular factual contexts — not readily, or even usefully,
reduced to a neat set of legal rules.” Id. at 232; see also
United States v. Gourde, 440 F.3d 1065, 1071 (9th Cir. 2006)
(en banc) (“Employing the principles of Gates — practicality,
common sense, a fluid and nontechnical conception of proba-
ble cause, and deference to the magistrate’s determination —
we conclude that the search warrant was supported by proba-
ble cause.”).

   [2] The warrant here was supported by probable cause,
because the affidavit submitted to the magistrate judge estab-
lished that “there [was] a fair probability that contraband or
evidence of a crime [would] be found in” computers at
Adjani’s residence.3 See Gates, 462 U.S. at 238. The exten-
  3
   Our conclusion that the agents could permissibly search Reinhold’s
computer does not rely upon the government’s assertion that Adjani and
Reinhold had “joint computers.”
                    UNITED STATES v. ADJANI                7587
sive 24-page supporting affidavit described the extortion
scheme in detail, including that Adjani possessed a computer-
generated database and communicated with Paycom over
email, requiring the use of a computer. Cf. Gourde, 440 F.3d
at 1072 (“The details provided on the use of computers by
child pornographers and the collector profile strengthen th[e]
inference [that probable cause supported the warrant] and help
‘provide[ ] context’ for the ‘fair probability’ that Gourde
received or downloaded images.” (internal citation omitted)).
Furthermore, the agent’s affidavit explained the need to
search computers, in particular, for evidence of the extortion
scheme: “I know that considerable planning is typically per-
formed to construct and consummate an extortion. The plan
can be documented in the form of a simple written note or
more elaborate information stored on computer equipment.”

   [3] “Probable cause exists if ‘it would be reasonable to seek
the evidence in the place indicated in the affidavit.’ ” United
States v. Wong, 334 F.3d 831, 836 (9th Cir. 2003) (quoting
United States v. Peacock, 761 F.2d 1313, 1315 (9th Cir.
1985)). The crime contemplated by the warrant was transmit-
ting a threatening communication with intent to extort. See 18
U.S.C. § 875(d). To find evidence of extortion, the govern-
ment would have probable cause to search for and seize
instrumentalities likely to have been used to facilitate the
transmission. The magistrate judge could rightfully assume
that there was a “fair probability” that such evidence could be
contained on computers or storage devices found in Adjani’s
residence.

  2.   Probable cause to search “Reinhold’s computer”

   [4] Having held that the affidavit supporting the warrant
established probable cause to search for and seize instrumen-
talities of the extortion (including records, files and comput-
ers) in Adjani’s residence, we turn to Reinhold’s contention
that the probable cause for the Adjani warrant did not extend
so far as to permit a search of her property. We disagree. The
7588                   UNITED STATES v. ADJANI
agents, acting pursuant to a valid warrant to look for evidence
of a computer-based crime, searched computers found in
Adjani’s residence and to which he had apparent access. That
one of the computers actually belonged to Reinhold did not
exempt it from being searched, especially given her associa-
tion with Adjani and participation (however potentially innoc-
uous) in some of his activities as documented in the agent’s
supporting affidavit.4 The officers therefore did not act unrea-
sonably in searching Reinhold’s computer as a source of the
evidence targeted by the warrant. See Illinois v. Rodriguez,
497 U.S. 177, 185 (1990) (holding Fourth Amendment
requires officers to act reasonably in executing a search war-
rant); Brinegar v. United States, 338 U.S. 160, 176 (1949).

   Reinhold’s argument that there was no probable cause to
search her computer, a private and personal piece of property,
because the warrant failed to list her as a “target, suspect, or
co-conspirator” misunderstands Fourth Amendment jurispru-
dence.5 Although individuals undoubtedly have a high expec-
tation of privacy in the files stored on their personal
computers, we have never held that agents may establish
probable cause to search only those items owned or possessed
by the criminal suspect. The law is to the contrary. “The criti-
cal element in a reasonable search is not that the owner of the
property is suspected of crime but that there is reasonable
cause to believe that the specific ‘things’ to be searched for
and seized are located on the property to which entry is
  4
     The affidavit expressly referred to Reinhold multiple times, including
that: (1) Reinhold delivered the envelopes containing the threat to Paycom
partners; (2) after leaving his house and driving his car, Reinhold picked
Adjani up from the airport upon his return from Switzerland; and (3)
Adjani’s email address (cadjani@mac.com) was billed to Reinhold.
   5
     The district court appears to have agreed with Reinhold’s argument
when it noted that “[t]here’s not probable cause of any kind mentioned in
the search warrant itself to deal with any property of Ms. Reinhold.” How-
ever, as we explain below, probable cause analysis focuses not on the
owner of the property, but rather on whether evidence of the crime can be
found on the property given the circumstances.
                    UNITED STATES v. ADJANI                  7589
sought.” Zurcher v. Stanford Daily, 436 U.S. 547, 556 (1978);
cf. United States v. Ross, 456 U.S. 798, 820-21 (1982) (“A
lawful search of fixed premises generally extends to the entire
area in which the object of the search may be found and is not
limited by the possibility that separate acts of entry or opening
may be required to complete the search.”).

   [5] In United States v. Hay, 231 F.3d 630 (9th Cir. 2000),
the defendant made an argument similar to Reinhold’s, chal-
lenging the district court’s ruling allowing evidence of child
pornography found on his computer to be used against him at
trial. Hay claimed that the affidavit submitted by officers to
obtain a warrant did not establish probable cause to engage in
a search of Hay’s computer because “there was no evidence
that he fell within a class of persons likely to collect and traf-
fic in child pornography because the affidavit does not indi-
cate that he was a child molester, pedophile, or collector of
child pornography and sets forth no evidence that he solicited,
sold or transmitted child pornography.” Id. at 635. We
rejected Hay’s challenge, holding that “[i]t is well established
that a location can be searched for evidence of a crime even
if there is no probable cause to arrest the person at the loca-
tion.” Id. (citing Zurcher, 436 U.S. at 556). See also United
States v. Taketa, 923 F.2d 665, 674 (9th Cir. 1991) (“[T]he
correct inquiry is whether there was reasonable cause to
believe that evidence of . . . misconduct was located on the
property that was searched.”); United States v. Tehfe, 722
F.2d 1114, 1118 (3d Cir. 1983) (“Property owned by a person
absolutely innocent of any wrongdoing may nevertheless be
searched under a valid warrant.”); United States v. Melvin,
596 F.2d 492, 496 (1st Cir. 1979) (holding the Zurcher rule
applies to “a person who the police do indeed suspect but do
not have probable cause to arrest; such a person’s property
may be searched upon probable cause to believe that fruits,
instrumentalities, or evidence of the crime are present, even
though the products of the search may implicate him.”).
7590                  UNITED STATES v. ADJANI
   [6] Likewise, there was no need here for the agents
expressly to claim in the affidavit that they wanted to arrest
Reinhold, or even that Reinhold was suspected of any crimi-
nal activity. The government needed only to satisfy the magis-
trate judge that there was probable cause to believe that
evidence of the crime in question — here extortion — could
be found on computers accessible to Adjani in his home,
including — as it developed — Reinhold’s computer.6 By set-
ting forth the details of the extortion scheme and the instru-
mentalities of the crime, augmented by descriptions of
Reinhold’s involvement with Adjani, the government satisfied
its burden. The magistrate judge therefore properly approved
the warrant, which in turn encompassed all the computers
found at Adjani’s residence.

B.     Specificity Requirement

   The defendants argue that if the warrant did authorize a
search that properly included Reinhold’s computer, the war-
rant was fatally overbroad, justifying the district court’s
exclusion of the Reinhold emails. The government counters
that the warrant satisfied the particularity standards articulated
by this court, so exclusion was improper.

   [7] The Fourth Amendment’s specificity requirement pre-
vents officers from engaging in general, exploratory searches
by limiting their discretion and providing specific guidance as
to what can and cannot be searched and seized. See United
States v. McClintock, 748 F.2d 1278, 1282 (9th Cir. 1984)
(“[G]eneral warrants are prohibited.” (internal quotation
marks omitted)); United States v. Cardwell, 680 F.2d 75, 77
(9th Cir. 1982) (“Nothing is left to the discretion of the officer
executing the warrant.” (internal quotation marks and citation
omitted)). However, the level of detail necessary in a warrant
  6
   The warrant signed by the magistrate judge plainly authorized a search
of all computers, hard drives, computer disks and other computer storage
devices in the Adjani residence.
                    UNITED STATES v. ADJANI                 7591
is related to the particular circumstances and the nature of the
evidence sought. See United States v. Spilotro, 800 F.2d 959,
963 (9th Cir. 1986). “Warrants which describe generic catego-
ries of items are not necessarily invalid if a more precise
description of the items subject to seizure is not possible.” Id.

  In determining whether a warrant is sufficiently particular,
we consider one or more of the following factors:

    (1) whether probable cause exists to seize all items
    of a particular type described in the warrant; (2)
    whether the warrant sets out objective standards by
    which executing officers can differentiate items sub-
    ject to seizure from those which are not; and (3)
    whether the government was able to describe the
    items more particularly in light of the information
    available to it at the time the warrant was issued.

Id. at 963 (internal citations omitted).

   Spilotro involved a warrant issued against individuals sus-
pected of loan sharking and gambling activities. See id. at
960. The warrant authorized “the seizure of address books,
notebooks, notes, documents, records, assets, photographs,
and other items and paraphernalia evidencing violations of the
multiple criminal statutes listed.” Id. at 964. It failed, how-
ever, to state the “precise identity, type, or contents of the
records sought.” Id. Partly because of this reason, we held
that the warrant was not sufficiently specific to pass muster
under the Fourth Amendment. More could have been done to
tie the documents sought to the crimes alleged by, for exam-
ple, stating that the police were searching for “records relating
to loan sharking and gambling, including pay and collection
sheets, lists of loan customers, loan accounts and telephone
numbers . . . .” Id. (internal quotation marks and citation omit-
ted).

   [8] In contrast to Spilotro, the warrant to search Adjani’s
residence satisfied our specificity criteria. First, we have
7592                UNITED STATES v. ADJANI
already held that there was probable cause to search the com-
puters. As to the second factor, the warrant objectively
described the items to be searched and seized with adequate
specificity and sufficiently restricted the discretion of agents
executing the search. The warrant affidavit began by limiting
the search for evidence of a specific crime — transmitting
threatening communications with intent to commit extortion.
See id. (“Reference to a specific illegal activity can, in appro-
priate cases, provide substantive guidance for the officer’s
exercise of discretion in executing the warrant.”); see also
United States v. Wong, 334 F.3d 831, 837-38 (9th Cir. 2003)
(“The specificity of the items listed in the warrant combined
with the language . . . directing officers to ‘obtain data as it
relates to this case’ from the computers is sufficiently specific
to focus the officer’s search.”); Cardwell, 680 F.2d at 76-77
(holding impermissibly general a warrant where “the only
limitation on the search and seizure of appellants’ business
papers was the requirement that they be the instrumentality or
evidence of violation of the general tax evasion statute,” but
noting that if the warrant is cabined by a “preambulatory
statement limiting the search to evidence of particular crimi-
nal episodes,” it may fulfill the particularity requirement).
Further, unlike in Spilotro, the Adjani warrant provided the
“precise identity” and nature of the items to be seized. Spi-
lotro, 800 F.2d at 964. For example, paragraph 5h of the war-
rant instructed agents to search for documents reflecting
communications with three individuals or other employees of
a specific company. Also, paragraph 5i authorized seizure of
“any” evidence of travel but provided a specific, though not
exhaustive, list of possible documents that fell within this cat-
egory and temporally restricted the breadth of the search. Cf.
United States v. Abrams, 615 F.2d 541, 543 (1st Cir. 1980)
(cited favorably in Cardwell, 680 F.2d at 77-78) (holding a
warrant was not sufficiently particular because “[t]he officers’
discretion was unfettered, there is no limitation as to time and
there is no description as to what specific records are to be
seized.”). Moreover, the extensive statement of probable
                      UNITED STATES v. ADJANI                      7593
cause in the affidavit detailed the alleged crime and Adjani’s
unlawful scheme. See Spilotro, 800 F.2d at 964 (considering
favorably warrants “describing the criminal activit[y] . . .
rather than simply referring to the statute believed to have
been violated.”).

   [9] With respect to the final Spilotro factor, we conclude
that the government described the items to be searched and
seized as particularly as could be reasonably expected given
the nature of the crime and the evidence it then possessed.
The Adjani warrant “describe[d] in great[ ] detail the items
one commonly expects to find on premises used for the crimi-
nal activities in question. . . .” Spilotro, 800 F.2d at 964; see
also United States v. Mann, 389 F.3d 869, 877 (9th Cir. 2004)
(“While a search warrant must describe items to be seized
with particularity sufficient to prevent a general, exploratory
rummaging in a person’s belongings, it need only be reason-
ably specific, rather than elaborately detailed.”) (internal quo-
tation marks and citation omitted).

   Center Art Galleries-Hawaii, Inc. v. United States, 875
F.2d 747 (9th Cir. 1989), the principal case defendants rely
upon in making their overbreadth argument, is distinguish-
able. In that case, we held that a warrant providing for “the
almost unrestricted seizure of items which are ‘evidence of
violations of federal criminal law’ without describing the spe-
cific crimes suspected is constitutionally inadequate.” Id. at
750 (quoting Spilotro, 800 F.2d at 964). In contrast, the gov-
ernment here did describe at some length both the nature of
and the means of committing the crime. Further, unlike in
Center Art Galleries, the affidavit was expressly incorporated
into the warrant. Id. (“An affidavit can cure the overbreadth
of a warrant if the affidavit is ‘attached to and incorporated
by reference in’ the warrant.”) (quoting Spilotro, 800 F.2d at
967, and citing United States v. Leary, 846 F.2d 592, 603
(10th Cir. 1988)).7
  7
   The supporting affidavit attached to the warrant set forth a detailed
computer search protocol, including instructions as to when the computers
7594                   UNITED STATES v. ADJANI
   We understand the heightened specificity concerns in the
computer context, given the vast amount of data they can
store. As the defendants urge, the warrant arguably might
have provided for a “less invasive search of Adjani’s [email]
‘inbox’ and ‘outbox’ for the addressees specifically cited in
the warrant, as opposed to the wholesale search of the con-
tents of all emails purportedly looking for evidence ‘reflect-
ing’ communications with those individuals.” Avoiding that
kind of specificity and limitation was not unreasonable under
the circumstances here, however. To require such a pin-
pointed computer search, restricting the search to an email
program or to specific search terms, would likely have failed
to cast a sufficiently wide net to capture the evidence sought.
Cf. Ross, 456 U.S. at 821 (“When a legitimate search is under
way, and when its purpose and its limits have been precisely
defined, nice distinctions between closets, drawers, and con-
tainers, in the case of a home, or between glove compart-
ments, upholstered seats, trunks, and wrapped packages, in
the case of a vehicle, must give way to the interest in the
prompt and efficient completion of the task at hand.”). More-
over, agents are limited by the longstanding principle that a
duly issued warrant, even one with a thorough affidavit, may
not be used to engage in a general, exploratory search. See

should be searched on-site rather than taken off-site and procedures for
screening the data to determine what data could be searched and seized
under the terms of the warrant. See also U.S. Dep’t of Justice, Searching
and Seizing Computers and Obtaining Electronic Evidence in Criminal
Investigations 43, 69 (July 2002) (detailing what FBI agents should
include in warrants when they contemplate the need to search computers).
Such specificity increases our confidence that the magistrate judge was
well aware of what he was authorizing and that the agents knew the
bounds of their authority in executing the search. Cf. Hay, 231 F.3d at 636
(considering favorably an affidavit providing “that searches and seizures
of evidence from computers requires agents to seize all parts of a com-
puter system to be processed later by a qualified computer expert.”).
  The protocol, of course, does not eliminate the necessity that the proto-
col procedures and the materials seized or searched fall within the scope
of a properly issued warrant supported by probable cause.
                    UNITED STATES v. ADJANI                7595
United States v. Rettig, 589 F.2d 418, 423 (9th Cir. 1978)
(“Where evidence is uncovered during a search pursuant to a
warrant, the threshold question must be whether the search
was confined to the warrant’s terms. . . . [T]he search must be
one directed in good faith toward the objects specified in the
warrant or for other means and instrumentalities by which the
crime charged had been committed. It must not be a general
exploratory search . . . .” (internal quotation marks and alter-
ations omitted)); see also Franklin v. Foxworth, 31 F.3d 873,
875 (9th Cir. 1994) (“[T]he reasonableness of a search or sei-
zure depends not only on when it is made, but also on how it
is carried out.” (internal quotation marks omitted and empha-
sis in original)).

   Computer files are easy to disguise or rename, and were we
to limit the warrant to such a specific search protocol, much
evidence could escape discovery simply because of Adjani’s
(or Reinhold’s) labeling of the files documenting Adjani’s
criminal activity. The government should not be required to
trust the suspect’s self-labeling when executing a warrant. See
Guest v. Leis, 255 F.3d 325, 335 (6th Cir. 2001) (“Defendants
may legitimately have checked to see that the contents of the
directories corresponded to the labels placed on the directo-
ries. Suspects would otherwise be able to shield evidence
from a search simply by ‘misfiling’ it in a directory labeled
‘e-mail.’ ”); cf. United States v. Tamura, 694 F.2d 591, 595
(9th Cir. 1982) (“[A]ll items in a set of files may be inspected
during a search, provided that sufficiently specific guidelines
for identifying the documents sought are provided in the
search warrant and are followed by the officers conducting
the search.”).

C.   Scope of the Warrant

  Even assuming that the warrant was supported by probable
cause and was adequately specific such that a search of Rein-
hold’s computer and emails were permissible, Reinhold
argues that the actual emails sought to be introduced into evi-
7596                   UNITED STATES v. ADJANI
dence were outside the scope of the warrant. Again, we dis-
agree.

   [10] The three seized emails the government seeks to admit
clearly fall within the scope of paragraph 5h of the warrant
affidavit, authorizing seizure of “[r]ecords, documents and
materials which reflect communications with Christopher
Mallick, Clay Andrews, Joel Hall or other employees or offi-
cers of Paycom or Epoch,” which are relevant evidence of
violations of 18 U.S.C. § 875(d). Each email specifically
refers to communication with Joel Hall or one of the stated
companies (identifying them by name).8 Reinhold’s argument
that the term “reflect communications with” should be read
narrowly to cover only those emails sent between one of the
named Paycom employees and Adjani is nonsensical. The
government already had the emails sent between the victims
of the extortion and Adjani — obtained from the victims
themselves. The purpose of the warrant was to obtain further
and corroborating evidence of the extortion scheme and
Adjani’s criminal intent in communicating with the victims,
and the three emails plainly “reflect” the relevant communica-
tions specified in paragraph 5h.

   To the extent Reinhold argues that the emails were outside
the scope of the warrant because they implicated her in the
crime and supported a charge of conspiracy to commit extor-
tion (a crime not specifically mentioned in the warrant), we
reject the argument. There is no rule, and Reinhold points to
no case law suggesting otherwise, that evidence turned up
while officers are rightfully searching a location under a prop-
erly issued warrant must be excluded simply because the evi-
  8
    The first email, sent from Adjani to Reinhold, states, in relevant part,
“I sent Joel the message.” The second, a reply from Reinhold, states, “I
thought that you were going to wait until after today if they don’t respond
to send Joel an email?” The third, another email from Reinhold to Adjani,
states, “I assume you have read Joel’s fax by now. Funny or sucky thing
is that I had ran out the door just 3 minutes before he sent that to go to
a payphone to call Epoch . . . . A girl answered and I asked for Joel Hall.”
                   UNITED STATES v. ADJANI                     7597
dence found may support charges for a related crime (or
against a suspect) not expressly contemplated in the warrant.

   [11] In United States v. Beusch, 596 F.2d 871 (9th Cir.
1979), the defendants argued that certain seized items, includ-
ing two ledgers and a file, should be excluded because they
contained information unrelated to the suspect identified in
the warrant. The defendants claimed that the officers imper-
missibly engaged in a general search by not segregating out
those items implicating a third individual in the crime. We
rejected this proposition and refused to impose the burden of
segregation on the police. In so doing we held,

    All three items admittedly contained information
    seizable under the terms of the warrant and they
    therefore met the particularity requirement of the
    Fourth Amendment. As long as an item appears, at
    the time of the search, to contain evidence reason-
    ably related to the purposes of the search, there is no
    reason absent some other Fourth Amendment viola-
    tion to suppress it. The fact that an item seized hap-
    pens to contain other incriminating information not
    covered by the terms of the warrant does not compel
    its suppression, either in whole or in part. In so hold-
    ing we are careful to point out that we are discussing
    single files and single ledgers, i.e., single items
    which, though theoretically separable, in fact consti-
    tute one volume or file folder.

Id. at 877 (internal citation omitted). Beusch is analogous to
the situation at hand. The agents were rightfully searching
Reinhold’s computer for evidence of Adjani’s crime of extor-
tion. They were looking in Reinhold’s email program when
they came across information that was both related to the pur-
poses of their search and implicated Reinhold in the crime.
That the evidence could now support a new charge against a
new (but already identified) person does not compel its sup-
pression. On these facts, we disagree with the district court’s
7598                     UNITED STATES v. ADJANI
conclusion that the officers should have obtained a new
search warrant when they came across the incriminating
emails. In so concluding, we are careful to note that in this
case the evidence discovered was clearly related to the crime
referred to in the warrant. We need not decide to what extent
the government would be able to introduce evidence discov-
ered that the police knew, at the time of discovery, was not
related to the crime cited in the warrant. Cf. United States v.
Carey, 172 F.3d 1268, 1272-73 (10th Cir. 1999) (excluding
certain evidence of child pornography where the warrant
authorized only seizure of drug evidence and the detective
knew he was expanding the scope of the warrant, and holding
that the officer should have stopped the search and obtained
a new warrant.).

                            III.   Conclusion

   “The Fourth Amendment incorporates a great many spe-
cific protections against unreasonable searches and seizures.”
Beusch, 596 F.2d at 876-77. The contours of these protections
in the context of computer searches pose difficult questions.
Computers are simultaneously file cabinets (with millions of
files) and locked desk drawers; they can be repositories of
innocent and deeply personal information, but also of evi-
dence of crimes. The former must be protected, the latter discov-
ered.9 As society grows ever more reliant on computers as a
  9
   The fear that agents searching a computer may come across such per-
sonal information cannot alone serve as the basis for excluding evidence
of criminal acts. As the Supreme Court has noted in a different context:
      We recognize that there are grave dangers inherent in executing
      a warrant authorizing a search and seizure of a person’s papers
      that are not necessarily present in executing a warrant to search
      for physical objects whose relevance is more easily ascertainable.
      In searches for papers, it is certain that some innocuous docu-
      ments will be examined, at least cursorily, in order to determine
      whether they are, in fact, among those papers authorized to be
      seized. Similar dangers, of course, are present in executing a war-
                      UNITED STATES v. ADJANI                       7599
means of storing data and communicating, courts will be cal-
led upon to analyze novel legal issues and develop new rules
within our well established Fourth Amendment jurisprudence.
See Eric L. Probst and Kerri A. Wright, Using Their E-Words
Against Them, NEW JERSEY LAW JOURNAL, Jan. 30, 2006, at S1
(noting that tens of billions of emails are sent daily). The fact
of an increasingly technological world is not lost upon us as
we consider the proper balance to strike between protecting
an individual’s right to privacy and ensuring that the govern-
ment is able to prosecute suspected criminals effectively. In
this era of rapid change, we are mindful of Justice Brandeis’s
worry in Olmstead v. United States,

     Ways may some day be developed by which the
     Government, without removing papers from secret
     drawers, can reproduce them in court, and by which
     it will be enabled to expose to a jury the most inti-
     mate occurrences of the home . . . . Can it be that the
     Constitution affords no protection against such inva-
     sions of individual security?

277 U.S. 438, 474 (1928) (Brandeis, J., dissenting).

   We do not now have occasion to address the myriad com-
plex issues raised in deciding when a court should exclude
evidence found on a computer, but are satisfied that the agents
in this case acted properly in searching Reinhold’s computer
and seizing the emails in question here. The district court
erred in excluding these emails. Therefore, the district court’s

    rant for the “seizure” of telephone conversations. In both kinds
    of searches, responsible officials, including judicial officials,
    must take care to assure that they are conducted in a manner that
    minimizes unwarranted intrusions upon privacy.
Andresen v. Maryland, 427 U.S. 463, 482 n.11 (1976).
7600               UNITED STATES v. ADJANI
ruling on the motion to suppress is reversed, and this matter
is remanded for further proceedings consistent with this opin-
ion.

  REVERSED and REMANDED.
