US supreme court rules geofence warrants require constitutional privacy protections

The US supreme court has ruled that law enforcement’s use of sprawling warrants that sweep up smartphone location data requires privacy protections under the fourth amendment, in a boost to critics who view their use as an unconstitutional dragnet. Justice Elena Kagan wrote the majority opinion. The use of geofence warrants is widespread, and gives law enforcement agencies the power to compel tech companies to hand over sensitive cell phone data from people at or near crime scenes. Police agencies and the FBI have used geofence warrants to collect this information from individuals that fall within the radius of a virtual “fence” during a particular timeframe. They aren’t restricted to requesting data for precise targets. That has alarmed privacy advocates, who say these sweeping warrants can be overly broad in the area they target, as well as the length of time they cover. “If the government doesn’t need to … link something to a crime, it could monitor a protest or an abortion clinic or a gun range or a church or an AA meeting or a doctor’s office,” says Matthew Tokson, a law professor at the University of Utah. The Chatrie case focuses on local police’s pursuit of an armed bank robber in Richmond, Virginia. He fled with $195,000. Law enforcement tracked Okello Chatrie down through their use of geofence warrants. Chatrie had opted in to an optional Google “location history” feature that documented his location every few minutes. …