Chatrie v. United States · ¶21

In the last decade, Google’s Location History data has also served another function, though this one unknown to most users: That data, as obtained through a geofence warrant, can enable law enforcement officers to solve hard-tosolve crimes. Such a warrant, as earlier described, seeks information about the cell phones located in the vicinity of a crime scene at around the time the crime was committed. See supra, at 1. The goal, put simply, is to find out who was there and so who might have done it. (There are usually better ways to investigate an already-known suspect—like seeking only his location data.) And the mechanism is to use the offender’s cell phone as an identifying device. The warrant specifies a timeframe and maps an area (with the geofence as its perimeter), and demands information about the cell phones—and their users—present within it. There is some uncertainty about how…

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