In re Telephone Information Needed for a Criminal Investigation

119 F. Supp. 3d 1011, 2015 U.S. Dist. LEXIS 99871, 2015 WL 4594558
CourtDistrict Court, N.D. California
DecidedJuly 29, 2015
DocketCase No. 15-XR-90304-HRL-1(LHK)
StatusPublished
Cited by19 cases

This text of 119 F. Supp. 3d 1011 (In re Telephone Information Needed for a Criminal Investigation) is published on Counsel Stack Legal Research, covering District Court, N.D. California primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
In re Telephone Information Needed for a Criminal Investigation, 119 F. Supp. 3d 1011, 2015 U.S. Dist. LEXIS 99871, 2015 WL 4594558 (N.D. Cal. 2015).

Opinion

[1013]*1013ORDER AFFIRMING DENIAL OF APPLICATION FOR HISTORICAL CELL SITE LOCATION INFORMATION

[PUBLIC REDACTED VERSION]

LUCY H. KOH, United States District Judge

Before the Court is the government’s appeal of U.S. Magistrate Judge Howard R. Lloyd’s denial of an application for an order pursuant to 18 U.S.C. § 2703(d) authorizing the government to obtain historical cell site location information (“CSLI”) associated with [Redacted] target cell phones. ECF No. 4 (“Gov’t Br.”); ECF No. 5 (“Gov’t Supp. Br.”).1 The Federal Public Defender for the Northern District of California (“Public Defender”), at the Court’s invitation, filed a response. ECF No. 21 (“Opp.”). With the Court’s permission, the American Civil Liberties Union (“ACLU”) and. the Electronic Frontier Foundation (“EFF”) filed amicus briefs in support of the Public Defender. ECF No. 19 (“ACLU Br.”); ECF No. 20 (“EFF Br.”). The government replied. ECF No. 22 (“Gov’t Reply”). Having considered these written submissions, the relevant law, the record in this case, and the oral arguments presented at the June 24, 2015 hearing, the Court hereby AFFIRMS Judge Lloyd’s denial of the government’s application for historical CSLI.

I. BACKGROUND

A. Cell Phone Technology and CSLI

Cell phones operate through the use.of radio waves. To facilitate cell phone use, cellular service providers maintain a network of radio base stations — also known as cell towers — throughout their coverage areas. See Electronic Communications Privacy Act (ECPA) (Part II): Geolocation Privacy and Surveillance, Hearing Before the Subcomm. on Crime, Terrorism, Homeland Security, and Investigations, of the H. Comm, on the Judiciary, 113th Cong. 50 (2013) (written testimony of Prof. Matt Blaze, University of Pennsylvania) (“Blaze Testimony”), available at http:// www.judiciary.house.gov/index.cfm?a= [1014]*1014Files.Serve & File_id=91FBF844-052E-4743-9CCE-19168FA815D2. Most cell towers have multiple cell sectors (or “cell sites”)- facing in different directions. ECF No. 22-1, Declaration of Special Agent Hector M. Luna (“Luna Decl.”) ¶ 3A. A cell site, in turn, is a specific portion of the cell tower, containing a wireless, antenna, which detects, the radio signal emanating from a cell phone and connects the cell phone to the local cellular network or Internet. Blaze Testimony at 50. For instance, if a cell tower has three antennas, each corresponding cell site would service an area within á 120-degree arc. See Thomas A. O’Malley, Using Historical Cell Site Analysis Evidence in Criminal Trials, U.S. Att’y Bull., Nov. 2011, at 19, available at http://www.justice.gov/usao/ eousa/foia_readmg_room/usab5906.pdf.

Whenever a cell phone makes or receives a call, sends or receives a text message, or otherwise sends or receives data, the phone connects via radio waves to an antenna on the closest cell tower, generating CSLI. The resulting CSLI includes the precise location of the cell tower and cell site serving the subject cell phone during each voice call, text message, or data connection. Luna ¶ 3A. If a cell phone moves away from the cell tower with which it started a call and closer to another cell tower, the phone connects seamlessly to that next tower. Blaze Testimony at 50.

Significantly, the government’s special agent from the Federal Bureau of Investigation (“FBI”) informs the Court that CSLI may be generated in the absence of user interaction with the cell phone. Luna Decl. ¶ 3B. For example, CSLI may still be generated during an incoming phone call that is not answered. Id. Additionally, most modern smartphones have applications that continually run in the background, sending and receiving data without a user having to interact with the cell phone. Id.

Indeed, cell phones, when turned on and not in airplane mode, are always scanning their network’s cellular environment. Luna Decl. ¶ 3B. In so doing, cell phones periodically identify themselves to the closest cell tower — i.e., the one with the strongest radio signal — as they move throughout their network’s coverage area. Blaze Testimony at 50, This process, known as “registration” or “pinging,” facilitates the making and receiving of calls, the sending and receiving of text messages, and the sending and receiving of cell phone data. See id. Pinging is automatic and occurs whenever the phone is on, without the user’s input or control. U.S. Dep’t of Homeland Sec., Lesson Plan: How Cell Phones Work 9 (2010) (“DHS Lesson Plan”), available at https://www. eff.org/files/filenode/3259_hpw_celL phones_work_lp.pdf. A cell phone that is switched on will ping the nearest tower every seven to nine minutes. Id. At oral argument, the Court was informed that at least some cellular service providers keep track of the CSLI generated by registration “pings.” Hr’g Tr. at 4:19-5:6.

As the number of cell phones has increased, the number of cell towers — and thus cell sites — has increased accordingly:

A sector can handle only a limited number of simultaneous call connections given the amount of radio spectrum “bandwidth” allocated to the wireless carrier. As the density of cellular users grows in a given area, the only way for a carrier to accommodate more customers is to divide the coverage area into smaller and smaller sectors, each served by its own base station and antenna. New services, such as 36 and LTE/46 Internet create additional pressure on the available spectrum bandwidth, usually requiring, again, that the area covered by each sector be made. smaller and smaller*.

[1015]*1015Blaze Testimony at 54. Densely populated urban areas therefore have more cell towers covering smaller geographic locations. For example, the Public Defender informs the Court that within three miles of the San Jose Federal Courthouse, there are 199 towers (with applications for three more currently pending) and 652 separate antennas. Opp. at 3. Within just one mile of the Federal Courthouse in New York City, there are 118 towers and 1,086 antennas. Id.

In addition to the large, three-sided cell towers, smaller and smaller base stations are becoming increasingly common. Examples include microcells, picocells, and femtocells, all of which cover a very specific area, such as one floor of a building, the waiting room of an office, or a single home. Blaze Testimony at 43-44. This proliferation of base stations to cover smaller areas means that “knowing the identity of the base station (or sector ID) that handled a call is tantamount to knowing a phone’s location to within' a relatively small geographic area ... sometimes effectively identifying individual floors and rooms within buildings.” Id. at 55-56. Although the ability of cellular service providers to track a cell phone’s location within an area covered by a particular cell, site might vary, it has become ever more.possible for the government to use CSLI to calculate a cell phone user’s “locations with a precision that approaches that of GPS.” Id. at 53.

The government acknowledged as much at oral argument, conceding that CSLI has gotten more precise over the years. Hr’g Tr' at 32:5-9. The fact is new tools and techniques are continually being developed to track CSLI with greater precision.

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119 F. Supp. 3d 1011, 2015 U.S. Dist. LEXIS 99871, 2015 WL 4594558, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-telephone-information-needed-for-a-criminal-investigation-cand-2015.