Case5:15-xr-90304-HRL Document30 Filed07/29/15 Page2 of 46 1 Public Defender. ECF No. 19 (“ACLU Br.”); ECF No. 20 (“EFF Br.”). The government replied. 2 ECF No. 22 (“Gov’t Reply”). Having considered these written submissions, the relevant law, the 3 record in this case, and the oral arguments presented at the June 24, 2015 hearing, the Court 4 hereby AFFIRMS Judge Lloyd’s denial of the government’s application for historical CSLI. 5 I. 6 United States District Court Northern District of California 7 BACKGROUND A. Cell Phone Technology and CSLI Cell phones operate through the use of radio waves. To facilitate cell phone use, cellular 8 service providers maintain a network of radio base stations—also known as cell towers— 9 throughout their coverage areas. See Electronic Communications Privacy Act (ECPA) (Part II): 10 Geolocation Privacy and Surveillance, Hearing Before the Subcomm. on Crime, Terrorism, 11 Homeland Security, and Investigations, of the H. Comm. on the Judiciary, 113th Cong. 50 (2013) 12 (written testimony of Prof. Matt Blaze, University of Pennsylvania) (“Blaze Testimony”), 13 available at http://www.judiciary.house.gov/index.cfm?a=Files.Serve&File_id=91FBF844-052E- 14 4743-9CCE-19168FA815D2. Most cell towers have multiple cell sectors (or “cell sites”) facing 15 in different directions. ECF No. 22-1, Declaration of Special Agent Hector M. Luna (“Luna 16 Decl.”) ¶ 3A. A cell site, in turn, is a specific portion of the cell tower containing a wireless 17 antenna, which detects the radio signal emanating from a cell phone and connects the cell phone to 18 the local cellular network or Internet. Blaze Testimony at 50. For instance, if a cell tower has 19 three antennas, each corresponding cell site would service an area within a 120-degree arc. See 20 Thomas A. O’Malley, Using Historical Cell Site Analysis Evidence in Criminal Trials, U.S. Att’y 21 Bull., Nov. 2011, at 19, available at http://www.justice.gov/usao/eousa/foia_reading_ 22 room/usab5906.pdf. 23 Whenever a cell phone makes or receives a call, sends or receives a text message, or 24 otherwise sends or receives data, the phone connects via radio waves to an antenna on the closest 25 cell tower, generating CSLI. The resulting CSLI includes the precise location of the cell tower 26 and cell site serving the subject cell phone during each voice call, text message, or data 27 28 2 Case No. 15-XR-90304-HRL-1(LHK) ORDER AFFIRMING DENIAL OF APPLICATION FOR HISTORICAL CELL SITE LOCATION INFORMATION