Why Two Hours and a Third Party Still Matter

The Supreme Court’s holding in Chatrie answers the threshold search question, but it does not make every boundary argument disappear. The live comparison is between a short record of public movement that a user chose to share with Google and a precise, expandable, traceable movement history that police can select from a much larger store. Understanding that comparison helps explain both the dissenting views and the more conditional approach offered by some Fourth Circuit judges, without turning any one of those approaches into a universal safe harbor.

The case for a brief public trip

The strongest argument against treating the Virginia geofence as a search begins with what police actually received. The warrant covered a 150-meter area around a public credit union and a one-hour window surrounding the robbery. At the next stage, the government obtained two hours of movement information for a smaller group. Under this view, the government did not acquire a long-term chronicle of anyone’s life. It obtained a single, brief trip associated with a public place.

That distinction draws support from older location cases. In United States v. Knotts, the Supreme Court held that a beeper used to follow a vehicle on public roads did not trigger the Fourth Amendment. A person traveling on public thoroughfares exposes those movements to anyone who wants to look, and the beeper largely helped officers do what they could have done by following the car. The Fourth Circuit opinions that found no search treated the Chatrie warrant as closer to that short public observation than to the 28-day GPS monitoring in United States v. Jones or the historical records covering days in Carpenter.

The public setting matters under this argument because a person generally cannot claim the same privacy in a bank’s public surroundings as inside a home. The dissenting Supreme Court opinions emphasized that the geofence was centered on a credit union, not on a private residence. They acknowledged that the process could capture travel outside the circle, but characterized any exposure of a private destination as incidental to an otherwise permissible inquiry into public movements. On that reasoning, the fact that a two-hour record could in theory reveal something sensitive does not establish that this particular search invaded Chatrie’s privacy.

The same argument treats the data’s brevity as a meaningful limit. A single trip does not necessarily show what a person does repeatedly, what they avoid, or how their routines fit together. Those patterns can reveal more than an isolated journey, and the Fourth Circuit had previously used that distinction when evaluating a citywide aerial-surveillance system. The no-search position applies the same logic in reverse: if two hours cannot produce a pattern of habits, then the record is less like the “detailed, encyclopedic” chronicle in Carpenter and more like a limited business record or public observation.

That position also relies on the way Location History was enabled. Unlike cell-site records, which a phone generates as a byproduct of ordinary network use, Location History was off by default in the record before the courts. A user had to activate the setting, and the service offered useful features such as a travel Timeline, maps, and traffic updates. A user could later review, edit, delete, or pause the collection. The Richardson and Wilkinson opinions therefore treated the record as information that Chatrie knowingly and voluntarily exposed to Google.