Geofence warrants, which require tech companies to cough up data on everyone in a certain geographic area at a certain time, have become an incredibly powerful tool for law enforcement. Sending a geofence warrant to Google, in particular, has come to be seen as almost an “easy button” among police investigators, given that Google has long stored location data on users in the cloud, where it can be demanded to help police identify suspects based on the timing and location of a crime alone—a practice that has appalled privacy advocates and other critics who say it violates the Fourth Amendment. Now, Google has made technical changes to rein in that surveillance power.

The company announced this week that it would store location history only on users’ phones, delete it by default after three months, and, if the user does choose to store it in a cloud account, keep it encrypted so that even Google can’t decrypt it. The move has been broadly cheered by the privacy and civil liberties crowds as a long-overdue protection for users. It will also strip law enforcement of a tool it had come to increasingly rely on. Geofence warrants were sent to Google, for instance, to obtain data on more than 5,000 devices present at the storming of the US Capitol on January 6, 2021, but they have also been used to solve far smaller crimes, including nonviolent ones. So much for the “easy button.”