EFF: New Federal Court Rulings Find Geofence Warrants Unconstitutional by Jennifer Lynch and Nathaniel Sobel:
Two federal magistrate judges in three separate opinions have ruled that a geofence warrant violates the Fourth Amendment’s probable cause and particularity requirements. Two of these rulings, from the federal district court in Chicago, were recently unsealed and provide a detailed constitutional analysis that closely aligns with arguments EFF and others have been making against geofence warrants for the last couple years.
Geofence warrants, also known as reverse location searches, are a relatively new investigative technique used by law enforcement to try to identify a suspect. Unlike ordinary warrants for electronic records that identify the suspect in advance of the search, geofence warrants essentially work backwards by scooping up the location data from every device that happened to be in a geographic area during a specific period of time in the past. The warrants therefore allow the government to examine the data from individuals wholly unconnected to any criminal activity and use their own discretion to try to pinpoint devices that might be connected to the crime. Earlier this summer, EFF filed an amicus brief in People v. Dawes, a case in San Francisco Superior Court, arguing that a geofence warrant used there violates deep-rooted Fourth Amendment law.