Geofence and reverse keyword warrants are some of the most dangerous, civil-liberties-infringing and reviled tools in law enforcement agencies’ digital toolbox. It turns out that these warrants are so invasive of user privacy that big tech companies like Google, Microsoft, and Yahoo are willing to support banning them. The three tech giants have issued a public statement through a trade organization,“ Reform Government Surveillance ,'' that they will support a bill before the New York State legislature. The Reverse Location Search Prohibition Act, A. 84 / S. 296, would prohibit government use of geofence warrants and reverse warrants, a bill that EFF also supports . Their support is welcome, especially since we’ve been calling on companies like Google, which have a lot of resources and a lot of lawyers, to do more to resist these kinds of government requests.
Under the Fourth Amendment, if police can demonstrate probable cause that searching a particular person or place will reveal evidence of a crime, they can obtain a warrant from a court authorizing a limited search for this evidence. In cases involving digital evidence stored with a tech company, this typically involves sending the warrant to the company and demanding they turn over the suspect’s digital data.