SCOTUS Decision: Law Enforcement's Use of 'Geofence Warrant' Was a 'Search'
The U.S. Supreme Court ruled that law enforcement's use of a "geofence warrant" to obtain location data from Google constitutes a "search" under the Fourth Amendment, requiring probable cause and a warrant. The decision curtails the ability of police to demand tech companies for anonymous location data of everyone near a crime scene without individualized suspicion.
Background
- **Geofence warrant (aka "reverse-location warrant")**: A court order demanding a tech company (e.g. Google) identify every device that was inside a specific geographic area during a specific time window. It starts with a location, not a suspect — a digital dragnet.
- **Fourth Amendment**: Protects against "unreasonable searches." The key question: does getting your location history from a company count as a "search"? If yes, police generally need a warrant backed by probable cause.
- **Prior context**: In a 2018 landmark case (*Carpenter v. U.S.*), the Supreme Court ruled police need a warrant to access weeks of cell-site location records. This new ruling applies that reasoning to geofence warrants specifically.
- **Why it matters**: Geofence warrants have become a routine law enforcement tool, used in cases from arson to abortion investigations. The ruling limits their use, reinforcing that Fourth Amendment protection isn't lost just because your data sits with a third party.