United States District Court, C.D. California, Southern Division
ORDER DENYING DEFENDANT’S MOTION TO
SUPPRESS
CORMAC
J. CARNEY UNITED STATES DISTRICT JUDGE
I.
INTRODUCTION AND BACKGROUND
In
December 2014, a foreign law enforcement agency advised the
FBI that a known child pornography website called
“Playpen” appeared to be associated with a United
States-based IP address.[1] (Dkt. 32 Ex. A at 6-37
[“Macfarlane Aff.”] ¶ 28.) An ensuing
investigation confirmed that Playpen was hosted by a server
located in North Carolina. (Id.) The FBI obtained a
search warrant for the location of the server in January
2015, seized the server, and found a copy of Playpen on it.
(Id.)
Playpen
operated as a “hidden service” located on an
anonymity network known as “The Onion Router, ”
or “Tor.” (Macfarlane Aff. ¶¶ 6-7.)
Ordinarily, public websites log the IP addresses of all
visiting users. It is therefore an easy task for law
enforcement to discover who has visited a certain website-or,
alternatively, which websites a computer with a particular IP
address has visited. The Tor network does not operate this
way. Instead, to even access the network, a user must first
download and install particular software, which subsequently
shields the user’s IP address by relaying it among
“nodes”-computers run by volunteers all over the
world. (Id. ¶ 8.) When a user visits a website
located on the Tor network-like Playpen, for example-his
actual IP address is not shown. Instead, Playpen can only see
the IP address of the Tor “exit node”-the final
relay computer which sent the user’s communication to
Playpen. (Id.) This deliberate concealment of IP
addresses makes it exceptionally difficult for law
enforcement to determine who has visited a website or hidden
service located on the Tor network, as there is no practical
way to trace a user’s IP address back through the Tor
nodes. (Id.)
Once on
the Tor network, a user must know a website’s
particular web address to visit it. (He may not, as on the
traditional or “open” Internet, simply perform an
Internet search for certain material, since websites on the
Tor network are not indexed like websites on the open
Internet.) (Macfarlane Aff. ¶ 10.) Tor users must obtain
web addresses from each other, or by viewing Internet
postings describing the content available on certain
websites. (Id.) The Tor network contains a
“hidden service” page that is dedicated to
pedophilia and child pornography, and Playpen’s web
address is listed on that page. (Id.) It would be
highly unusual for a user to stumble upon Playpen. He would
first have to elect to download Tor software and access the
“dark web, ” where Tor websites are hosted, and
then he would be required to affirmatively locate
Playpen’s web address before reaching Playpen.
Users
who entered Playpen’s web address arrived at a main
page which contained images of two partially clothed
prepubescent females with their legs spread apart, along with
text stating, “No cross-board reposts, .7z preferred,
encrypt filenames, include preview, Peace out.”
(Macfarlane Aff. ¶ 12.) This text apparently referred to
a ban on posting material from other message boards, an
indication of which file compression method was preferable,
and instructions on what to include with posted materials.
(Id.) Adjacent to the text were fields for users to
enter login credentials, and a hyperlink for new users to
“register an account with Playpen.”
(Id.) Upon clicking the “register an
account” hyperlink, users were taken to additional text
which explained that Playpen required an email address but
that rather than entering their real email address, users
should simply enter a made-up address: “something that
matches the xxx@yyy.zzz pattern.”
(Id. ¶ 13.) Users who successfully registered
for the service by entering a false email address were then
taken to a page containing Playpen’s forums and
subforums. (Id. ¶ 14.)
Playpen
was entirely devoted to the publication and exchange of child
pornography. Its forums, where Playpen users could post
materials, bore titles such as “Jailbait
Videos”[2] (of both “Girls” and
Boys”), “Pre-teen Videos, ” “Pre-teen
Photos, ” and “Webcams” (again, divided by
gender), “Family Playpen - Incest, ” and
“Toddlers.” (Macfarlane Aff. ¶ 14.) Playpen
also maintained a “Kinky Fetish” forum that
included subforums like “Bondage, ”
“Peeing, ” “Scat, ” “Spanking,
” “Voyeur, ” and “Zoo.”
(Id.) In addition to these forums and subforums,
Playpen included three other important features. The first,
called “Playpen Image Hosting, ” allowed Playpen
users to upload links to images of child pornography.
(Id. ¶ 23.) The links were then available to
all registered Playpen users. (Id.) The second,
“Playpen File Hosting, ” similarly allowed users
to upload videos of child pornography, which were then
available to Playpen registered users. (Id. ¶
24.) The third, “Playpen Chat, ” permitted users
to post links to child pornography for other users who were
logged into Playpen Chat at the same time. (Id.
¶ 25.) The link to Playpen Chat was on Playpen’s
main index page. (Id.)
The
FBI’s review of Playpen’s forums and subforums,
as well as its Playpen Image Hosting, Playpen File Hosting,
and Playpen Chat features, revealed links to numerous
depictions of what appeared to be child pornography. A
representative sampling of those depictions is as follows:
. An image of a prepubescent or early
pubescent female being orally penetrated by the penis of a
naked male. (Macfarlane Aff. ¶ 18.)
. A video of a prepubescent female, naked
from the waist down, being anally penetrated by the penis of
a naked adult male. (Id. ¶ 18.)
. Images focused on the nude genitals of a
prepubescent female. (Id. ¶ 23.)
. A video of an adult male masturbating and
ejaculating into the mouth of a nude prepubescent female.
(Id. ¶ 24.)
. An image of two prepubescent females lying
on a bed with their genitals exposed. ( Id. ¶
25.)
. An image of four females, including at
least two prepubescent females, performing oral sex on one
another. (Id. ¶ 25.)
The FBI
seized a copy of the server hosting Playpen in January 2015.
(Macfarlane Aff. ¶ 28.) The nature of the Tor network,
however, prevented the FBI from identifying Playpen users,
since Playpen’s “logs of member activity . . .
contain[ed] only the IP addresses of Tor ‘exit
nodes’ utilized by board users.” (Id.
¶ 29.) Accordingly, on February 19, 2015, the FBI
executed a court-authorized search at the Naples, Florida
residence of the suspected administrator of Playpen.
(Id. ¶ 30.) The administrator was apprehended,
and the FBI managed to assume administrative control of
Playpen. (Id.) The FBI then devised a plan to
determine the identities of Playpen users: it would, while
running Playpen from a server in Virginia, reconfigure the
website to deploy a network investigative technique
(“NIT”) any time a user downloaded content from
Playpen. (Id. ¶ 33.) As Douglas Macfarlane, an
FBI Special Agent, subsequently explained,
In the normal course of operations, websites send content to
visitors. A user’s computer downloads that content and
uses it to display web pages on the user’s computer.
[Upon deployment of the NIT, Playpen, ] which will be located
in Newington, Virginia, . . . would augment that content with
additional computer instructions. When a user’s
computer successfully downloads those instructions from
[Playpen], the instructions, which comprise the NIT, are
designed to cause the user’s “activating”
computer to transmit certain information to a computer
controlled by or known to the government.
(Macfarlane Aff. ¶ 33.) Specifically, the NIT would
reveal to the government seven items:
1. The activating computer’s IP address, and the date
and time that the NIT determined what that IP address was;
2. A unique identifier generated by the NIT to distinguish
the data from that of other ...