In re Search of Info. That is Stored at the Premises Controlled by Google LLC

579 F.Supp.3d 62

In the MATTER OF the SEARCH OF INFORMATION THAT IS STORED AT the PREMISES CONTROLLED BY GOOGLE LLC.

Case No. 21-SC-3217 (GMH)

United States District Court, District of Columbia.

Signed December 30, 2021

Brooks H. Spears, McGuireWoods LLP, Tysons, VA, George J. Terwilliger, III, McGuireWoods LLP, Washington, DC, for Mark Meadows.

Douglas N. Letter, U.S. House of Representatives Office of General Counsel, Washington, DC, for Nancy Pelosi, Bennie G. Thompson, Elizabeth L. Cheney, Adam B. Schiff, Jamie B. Raskin, Susan E. Lofgren, Elaine G. Luria, Peter R. Aguilar, Stephanie Murphy, Adam D. Kinzinger, Select Committee to Investigate the January 6th Attack on the United States Capitol.

MEMORANDUM OPINION

G. MICHAEL HARVEY, UNITED STATES MAGISTRATE JUDGE

Imagine a homicide in an alley caught on a nearby surveillance camera. The video is clear enough to see the attack, but too grainy to identify who did it. It is obvious from the video, however, that the perpetrator is checking his cell phone as he walks out of the alley. Having determined the location and time of the killing from the video, would it be lawful for the police to obtain a warrant leveraging the tracking capability of mobile devices to identify whose cell phone was in the area of the crime when it occurred? On October 6, 2021, the Court was presented with a warrant that asked that question, albeit not in a homicide case.¹ Commonly referred to as a "geofence" warrant, the government's application asked the Court to direct technology company Google to identify, through a multi-step process, the cell phone users that crossed into a defined geographic area around where the criminal activity under investigation occurred.

Though geofence warrants raise a number of important constitutional questions, there is not much federal caselaw discussing their legality. As of the date of this decision, the Court could identify only four federal decisions, three of which denied the geofence warrant under consideration.² That seeming reluctance to grant such warrants does not appear to have slowed their acceptance by other courts and their use by law enforcement. According to a recent report, Google received over 11,554 geofence warrants in 2020, up from 982 in 2018; as of August 2021, they comprised nearly a quarter of all warrants served on Google.³ Each of those warrants was authorized by a judge. So, it would appear that many more geofence warrants are being granted by courts than denied.

On October 13, 2021, the Court granted the geofence warrant application at issue in this case. This memorandum opinion explains why it was granted and, in the process, adds to the limited federal caselaw discussing the legality of such warrants.

I. BACKGROUND

A. Geofence Warrants

Soon after the advent of smart phones with the capability to track the location of their users, law enforcement sought warrants, or other legal process, to obtain the Global Positioning System ("GPS") data such cell phones collect to track their users who were known to be engaging in criminal activity. See, e.g. , In re Application of U.S. for an Order Authorizing Disclosure of Location Information of a Specified Wireless Telephone , 849 F. Supp. 2d 526, 530 (D. Md. 2011). Often referred to as "GPS warrants," such warrants are, at this point, routine. They are frequently authorized, for example, to permit law enforcement to track a known or suspected drug dealer's cell phone to assist in locating the dealer's points of sale, drug stash houses, suppliers or co-conspirators. See, e.g. , United States v. Burnett , No. 12-CR-00042 2013 WL 12430549, at *2 n.4 (D.D.C. Mar. 21, 2013) (noting that the government sought search "warrants for GPS tracking data for [a suspect's] cellular telephone" as part of its investigation into drug trafficking), aff'd , 827 F.3d 1108 (D.C. Cir. 2016).

The warrant before the Court is different. It is what has been termed a "reverse-location" warrant: the perpetrator of the crime being unknown to law enforcement, the warrant identifies the geographic location where criminal activity happened and seeks to identify cell phone users at that location when the crime occurred. The "geofence" is the boundary of the area where the criminal activity occurred, and is drawn by the government using geolocation coordinates on a map attached to the warrant.⁴ See Google I , 2020 WL 5491763, at *1 (explaining that a geofence warrant "is a warrant to obtain cellular phone data generated in a designated geographic area"); see also United States v. Asghedom , 992 F. Supp. 2d 1167, 1169 (N.D. Ala. 2014) ("A ‘geofence’ is a perimeter set up around certain locations based on the [ ] coordinates of the locations."). The fence's boundary is quite flexible. Virtually any shape of any size that can be drawn using geographic coordinates can be used, including rectangles, triangles, or other irregular shapes, like the perimeter of a building or the length of a street. See Google III , 497 F. Supp. 3d at 351–52 (describing geofences constructed by the government as a triangle, an " ‘L’ shape," and a square). Further, circles can be constructed by instructing Google or other companies that store location information to collect data from a certain radius around a fixed point. The geofence is also bound by a time window dictated by when the crime is believed to have occurred (for example, between 1:00 p.m. and 1:15 p.m. on February 15, 2021). The time periods are also flexible; they can be as narrow or as broad as the facts of the criminal activity require and the law permits.

Understanding how Google obtains geolocation information from cell phones and the identities of their users is more complicated. Cell phones are basically "minicomputers that also happen to have the capacity to be used as a telephone." Riley v. California , 573 U.S. 373, 393, 134 S.Ct. 2473, 189 L.Ed.2d 430 (2014). And like computers, cell phones—including phones with Google's Android operating system ("OS")—need to "connect" with a variety of other devices in order to function. See Affidavit in Support of an Application for a Search Warrant ("Warrant Aff."), ¶ 7. For example, Google OS phones must connect with wireless internet ("wi-fi") devices in order to access the Internet. See id. Likewise, phones must use Bluetooth technology to connect to wireless headphones and other devices. See id. , ¶ 8 (explaining that "Bluetooth uses radio waves to allow the devices to exchange information").⁵ Similarly, when using the "map" function, Google OS phones use an internal GPS to ascertain the phones’ exact location. See id. , ¶ 9. When Google OS phones connect to the Internet via wi-fi or scan their environments for Bluetooth devices or use GPS, they send information on the phone's location to Google.⁶ See id. , ¶ 16. "Google uses this information to calculate the device's estimated latitude and longitude," and makes this information available for viewing by the phone's user in a service called "Location History" (the location information itself is stored on Google's servers). Id. , ¶¶ 14, 16. Phone users must opt in to the "Location History" service, and Google has said that, as of 2019, about one-third of Google users had done so.⁷ See id. , ¶ 17. But even when users opt out of Location History or other location tracking, Google can still track and store their device's location data.⁸ See id. , ¶ 19; see also Google II , 481 F. Supp. 3d at 737 n.3 ("Published reports have indicated that many Google services on Android and Apple devices store the device users’ location data even if the users seek to opt out of being tracked by activating a privacy setting that says it will prevent Google from storing the location data.").

Google also collects location information from phones that do not use Google OS (for example, iPhones) but nevertheless use Google applications, such as Gmail; YouTube; Google Maps; and Google's Internet browser, Chrome.⁹ See Warrant Aff., ¶ 19; see also Google III , 497 F. Supp. 3d at 350–51 (explaining that "Google apps exist for, and can be downloaded to, phones that do not run the Android operating system, such as Apple devices"). Google's Android OS is used by nearly 74 percent of the world's smartphone market, with a market share of approximately 46 percent in the U.S. See Warrant Aff., ¶ 19. But because iPhone users (who represent 23 percent of the worldwide market and 54 percent of the domestic market) also utilize Google applications on their devices—including Google Maps, YouTube, and Google's search engine—Google's cache of location information is even greater than its already-substantial market share suggests.¹⁰ See id.

The cell phone location information Google collects is usually quite accurate—to within 20 meters, according to Google. See Google Amicus Brief at 15. This is because it is derived from multiple sources of location information including not only GPS data, but also from cell sites or towers, wi-fi networks, and Bluetooth devices. See Warrant Aff., ¶ 16. However, the location information Google collects is not perfectly precise, and includes a margin of error. See id. , ¶ 15. Although the margin of error for each device depends on the quantity and quality of the location information the device transmitted to Google, Google says it aims to accurately capture the location of "at least 68% of users." Id. Simply put, when Google searches its servers for the devices within a defined location boundary, a device that is outside of the boundaries of the geofence may be listed as within the boundaries of the fence due to imprecision in calculating the device's exact location. Conversely, a device that was within the geofence may not be recorded as being there. Google aims to correctly locate about two-thirds or more of its users.

The final piece of the puzzle is connecting the location data Google collects back to a particular user. According to the warrant affidavit, Google does this by collecting a...