Submitted: April 6, 2017
from United States District Court for the Southern District
of Iowa - Council Bluffs
SMITH, Chief Judge, SHEPHERD, Circuit Judge and FENNER,
District Judge. 
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.
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 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.
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.
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
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.
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. 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
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.
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.
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 ...