United States District Court Northern District of California Case5:15-xr-90304-HRL Document30 Filed07/29/15 Page41 of 46 1 as to how long AT&T will keep records of a subscriber’s CSLI. In AT&T’s letter to Congress, 2 AT&T disclosed that it will store such data for five years. See ACLU Br. at 2 n.5 (citing Letter 3 from Timothy P. McKone, Executive Vice President, AT&T, to Rep. Edward J. Markey (Oct. 3, 4 2013)). Subscribers would not know that from the privacy policy. As the AT&T policy says 5 nothing about how long a cell phone user’s CSLI will be stored, the Court cannot conclude that 6 such a policy provides the basis for consent to the government’s acquisition of sixty days’ worth 7 of historical CSLI. 8 In addition, nowhere does the Verizon or AT&T privacy policy indicate the volume of 9 location data that is likely to be collected and stored by the provider. There is no estimate, for 10 example, of the number of location data points a typical user will generate over the course of an 11 hour, day, week, month, or year. This omission is especially problematic considering that the 12 sheer volume of CSLI generated by a user’s cell phone can be staggering. See Wessler Decl. ¶¶ 8- 13 10. In Davis, for instance, the government obtained the defendant’s CSLI for a period of sixty- 14 seven days. “During that time, Davis made or received 5,803 phone calls, so the prosecution had 15 11,606 data points about Mr. Davis’s location.” Davis, 785 F.3d at 533 (Martin, J., dissenting). 16 “This averages around one location data point every five and one half minutes for those sixty- 17 seven days, assuming Mr. Davis slept eight hours a night.” Id. at 540. 18 In light of the foregoing, the Court cannot conclude that cell phone users generally—or in 19 this instance—consent through the privacy policies of their cellular service providers to the 20 government’s warrantless acquisition of the historical CSLI associated with the users’ cell phones. 21 Because the government offers no other basis for its conduct to be excepted from the Fourth 22 Amendment’s warrant requirement, the Court holds that the government must, pursuant to Rule 41 23 of the Federal Rules of Criminal Procedure, secure a warrant supported by probable cause in order 24 to obtain a cell phone user’s historical CSLI. 25 26 27 28 This requirement does not impose an undue burden on the government. Indeed, the SCA expressly contemplates that the government may need to “obtain[] a warrant issued using the 41 Case No. 15-XR-90304-HRL-1(LHK) ORDER AFFIRMING DENIAL OF APPLICATION FOR HISTORICAL CELL SITE LOCATION INFORMATION