Cell phone location data and location history are usually turned on by most cell phone users. In a recent U.S. Supreme Court decision, the Court considered how the Fourth Amendment applies to a geofence warrant requesting cell site location information (“CSLI,” i.e., cell phone location data and location history).
In its June 29, 2026, decision in Chatrie v. United States, the Court commented on the ubiquitousness of cell phones: “Modern cell phones, we observed a dozen years ago, are ‘such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy.’”[1] These mobile technological wonders (which many people take for granted because of how they have become so integrated into their daily lives) collect and store a tremendous amount of detailed information about their owners’ lives. Some of that information is stored locally on the phone, and some in the “cloud” (e.g., the remote physical servers owned by the provider(s) of the location service functionality).
There are a lot of good reasons why most users activate location data and location history on their cell phones. This includes, without limitation, use of location-based functionalities on the phone such as using mapping/directions services, real-time updates on your daily commute, relevant location information of services near your location, and awareness of the location of loved ones who have consented to your knowing their location.
In Chatrie, local police in Virginia were trying to solve a crime involving a man robbing a credit union. As described in the syllabus, the police “learned from witness interviews and surveillance footage that the robber had approached the credit union from a corner of an adjacent church while appearing to talk on a cell phone, but they could not find out anything more, and the robber remained at large.”[2] The police applied to the local court for a geofence warrant directed to Google requesting CSLI within a certain radius of the credit union (the geofence) that Google collects through its Location History service, and described a three-step process that the police would follow: “[S]tep one, Google would produce anonymized location data for all cell phones within the geofence 30 minutes before to 30 minutes after the robbery; at step two, officers would attempt to narrow the list, and Google would provide additional anonymized data for that narrowed list, consisting of cell-phone locations both inside and outside the geofence during a two-hour period surrounding the robbery; and at step three, officers would further narrow the list, and Google would turn over identifying information, including names and phone numbers, for users on the final list.”[3] Based on that process, the federal government charged Okello Chatrie, petitioner, one of the individuals identified through that process, with committing the crime.
The Court was asked to consider whether the Fourth Amendment applied to (1) the use of a geofence warrant as described in the Court’s decision and, if so, (2) whether the search was reasonable given the features of the warrant they employed. The Court answered the first part of the question by holding that the police conducted a search when they gained access to Location History data, stating, “An individual has a reasonable expectation of privacy in records about his cell phone’s location, and police intrude on that constitutionally protected interest when they demand the information—even though for only a limited time, and from a third-party tech company.”[4] The Court stated further “The Fourth Amendment applies, too, when officials tap into Google’s ‘database of physical location information.’ Ibid. That database is new, but the principle covering it is not: That principle is instead the one our history has given.”[5] For the second part of the question (whether the search was reasonable given the warrant issued), the Court remanded to the Court of Appeals to determine whether the warrant issued and each of its steps were properly described with particularity and found to be supported by probable cause.
The bottom line is that the Fourth Amendment protects “against unjustified governmental intrusion on the privacy of the individual.”[6] The determination as to whether the search is reasonable depends on the facts. Nevertheless, the individual cell phone owner should read the fine print of agreements pertaining to cell phone location data and location history and knowingly exercise their freedom to choose whether to turn on or off that (and any other) cell phone functionality.
