By: Nicole Hurst
A geofence warrant is a relatively new use of technology to help law enforcement investigate crimes. Cellphone companies, specifically Google, have tracked and stored their users’ location data for years. A geofence warrant is a “formal request from law enforcement to a provider (usually Google) to provide the “Location History” data of every device within a defined geographic region and within a specific time frame.”[1] The police then use the location and the time frame to narrow down suspects and identify a device owner as the perpetrator of the crime.
Google first received geofence warrant requests in 2016, and the requests have increased exponentially over the last few years. From 2017 to 2018, the requests increased by 1,500%; by 2019, Google received about 180 weekly requests, or 9,000 for the year. By 2021, geofence warrants comprised more than 25% of all warrant requests Google received in the United States.[2]
Google developed a three-step procedure for responding to requests. The first step is for a law enforcement agent to provide Google with the “geographical and temporal parameters around the time and place where the alleged crime occurred.” Google cannot store the data in a way that permits a search of specific user data or individual accounts and must search its entire Senesorvault to respond to the request. Once Google completes the Sensorvault search, a list of accounts within the warrant’s geographic parameters is provided. The list is anonymous, and devices are tagged with an identifying code that hides their personal identifying information.
For the second step, law enforcement contextualizes and narrows the data once received from Google and determines which anonymous IDs are relevant. The IDs are then requested, and in step three, Google provides the account-identifying information to the police.[3] Law enforcement can then pursue further investigative techniques to locate the suspect. This is an example of the process used in Geofence warrants by one large company.
The Fifth Circuit issued a decision in United States v. Smith, broadly holding that geofence warrants are unconstitutional under the Fourth Amendment.[4] The Fifth Circuit held that accessing location records, no matter the geographical limit, is a violation of the Fourth Amendment, violating an individual’s reasonable expectation of privacy.[5]
Conversely, in United States v. Chatrie, the Fourth Circuit held that accessing location data for a limited time period did not constitute a search.[6] Judges have focused on the specifics of the warrant, noting the temporal length of the period for which historical location information is sought and the geographic scope of the area for which results will be deemed responsive.[7] The Court compared the collection of location information to Jones and Carpenter, noting that individuals have a reasonable expectation of privacy in their physical movements.[8]
Businesses should note these decisions, as they could ultimately lead to compliance issues in data retention. The lack of cohesive state privacy laws in the United States allows for flexibility in courts interpreting their definition of reasonableness. Businesses must be aware of differences in the court’s approach and could potentially use the decisions to initiate changes moving forward. For example, Google has decided to eliminate storing user locations in a large database and is switching to storing user locations on the individual’s physical device.[9] This change could be a sign of the times initiated by the Fifth Circuit’s decision. This action by Google may ultimately lead to more significant challenges for law enforcement.[10]
It is also important to note that location information is being stored by more than just Google. There are dozens of data brokers collecting information about precise movements, often being done without knowledge or even “meaningful consent.”[11] Most of this information comes from third-party applications on mobile phones such as weather, navigation, coupon apps, and “family safety” apps.[12] Once this information is collected, it can be sold to a variety of organizations, such as “hedge funds, insurance companies, advertisers, and government agencies such as the military, the FBI, and ICE.”[13]
Data brokers have operated for the most part in the shadows but have managed to create a multi-billion-dollar market for location data.[14] Smartphone applications have found many reasons to track location information without users thinking twice about it. Map apps need to know where a person is to provide directions, weather apps provide relevant meteorological information, and video streaming apps check where you are to ensure you are in a country licensed to stream certain shows.[15] Google’s change may change the approach by law enforcement for geofence warrants, but there is a vast network of data brokers that can provide the same, if not better, information for a fee.
The recent Fifth Circuit decision in Smith may have prompted Google to modify their data and location storage practices, but there are still many data brokers existing in the shadows that will continue to collect and sell location data.[16] This could force the hand of law enforcement and lead agencies to either purchase large amounts of location data or seek warrants that do not necessarily have the same limitations as Google previously required.[17] Until the privacy laws catch up with technology, there will continue to be a gap in protection. The contradicting decisions in the Fourth and Fifth Circuits do not provide any optimism that the gap will be closed any time soon.[18]
[1] Prathi Chowdri, Emerging Tech and Law Enforcement: What Are Geofences and How Do They Work?, Lexipol (Jan. 4, 2024), https://www.lexipol.com/resources/blog/emerging-tech-and-law-enforcement-what-are-geofences-and-how-do-they-work/.
[2] United States v. Smith, 110 F.4th 817, 822 (5th Cir. 2024).
[3] Id. at 824.
[4] Id. at 841.
[5] Holtzblatt et al., The Impact and Future of the Fifth Circuit’s New Hard-Line Stance on Geofence Warrants, WilmerHale (Aug. 27, 2024), https://www.wilmerhale.com/insights/client-alerts/20240827-the-impact-and-future-of-the-fifth-circuits-new-hard-line-stance-on-geofence-warrants.
[6] United States v. Chatrie, 590 F. Supp. 3d 901, 941 (4th Cir. 2022).
[7] Holzblatt, supra note 5, at 1.
[8] See Carpenter v. United States, 585 U.S. 296, 310 (2018); see also Jones v. United States, 526 U.S. 227, 251 (1999).
[9] Skye Witley, Google’s Location Data Move Will Reshape Geofence Warrant Use, Bloomberg L. (Dec. 20, 2023, 5:05 AM), https://news.bloomberglaw.com/privacy-and-data-security/googles-location-data-move-will-reshape-geofence-warrant-use.
[10] Lars Daniel, Google to Stop Giving Location Evidence to Law Enforcement, Forbes (Oct. 8, 2024), https://www.forbes.com/sites/larsdaniel/2024/10/08/google-to-stop-sharing-location-data-with-law-enforcement/.
[11] Location Data Brokers, Elec. Frontier Found., https://www.eff.org/issues/location-data-brokers (last visited Oct. 20, 2024).
[12] Id.
[13] Id.
[14] Jon Keegan & Alfred Ng, There’s a Multibillion-Dollar Market for Your Phone’s Location Data, The Markup (Sept. 30, 2021, 3:51 PM), https://themarkup.org/privacy/2021/09/30/theres-a-multibillion-dollar-market-for-your-phones-location-data.
[15] Id.
[16] Id.
[17] Bennett Cyphers, How Law Enforcement Around the Country Buys Cell Phone Location Data Wholesale, Electronic Frontier Found. (Aug. 31, 2022), https://www.eff.org/deeplinks/2022/08/how-law-enforcement-around-country-buys-cell-phone-location-data-wholesale.
[18] United States v. Smith, 110 F.4th 817, 817 (5th Cir. 2024); United States v. Chatrie, 590 F. Supp. 3d 901, 901 (4th Cir. 2022).