Ageofence warrant or areverse location warrant is asearch warrant issued by a court to allowlaw enforcement to search a database to find all activemobile devices within a particulargeo-fence area. Courts have granted law enforcement geo-fence warrants to obtain information from databases such asGoogle'sSensorvault, which collects users' historicalgeolocation data.[1][2] Geo-fence warrants are a part of a category of warrants known asreverse search warrants.[3]
Geofence warrants were first used in 2016.[4]Google reported that it had received 982 such warrants in 2018, 8,396 in 2019, and 11,554 in 2020.[3] A 2021 transparency report showed that 25% of data requests from law enforcement to Google were geo-fence data requests.[5] Google is the most common recipient of geo-fence warrants and the main provider of such data,[4][6] although companies includingApple,Snapchat,Lyft, andUber have also received such warrants.[4][5]
Some lawyers and privacy experts believe reverse search warrants are unconstitutional under theFourth Amendment to the United States Constitution, which protects people from unreasonablesearches and seizures, and requires any search warrants be specific to what and to whom they apply.[7] The Fourth Amendment specifies that warrants may only be issued "upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."[7] Some lawyers, legal scholars, and privacy experts have likened reverse search warrants togeneral warrants, which were made illegal by the Fourth Amendment.[7]
Groups including theElectronic Frontier Foundation have opposed geo-fence warrants inamicus briefs filed in motions to quash such orders to disclose geo-fence data.[8]
In 2024, a panel of theUnited States Fourth Circuit Court of Appeals considered data acquired from Google’s Sensorvault not to be a search, but non-private business records when users opt-in to Google’s location history.[9] However, upon a rehearing en banc, the Court vacated that decision. In April 2025, the full Court affirmed the judgment solely on the'good faith' exception, leaving the underlying constitutional question of whether geofence warrants constitute a search unsettled in the Circuit.[10]
However, theUnited States Fifth Circuit Court of Appeals found that geofence warrants are "categorically prohibited by the Fourth Amendment."[11] The split in Circuits may prompt theUnited States Supreme Court to hear the issue.[12]