The investigation included the largest number of phones in the history of controversial geofencing orders, court records show. A filing in the case of one of the January 6 suspects, David Rhine, shows that Google initially identified 5,723 devices that were in or near the US Capitol during the riots. Only about 900 people have so far been charged with crimes related to the siege.
Geofence search warrants are intended to locate anyone in a given area using digital services. Because Google’s Location History system is both powerful and widely used, the company is served about 10,000 geofence warrants in the US each year. Location History leverages GPS, Wi-Fi, and Bluetooth signals to pinpoint a phone within a few yards. Although the final location is still subject to some uncertainty, it is usually much more precise than triangulating signals from cell towers. Location History is turned off by default, but around a third of Google users switch it on, enabling services like real-time traffic prediction.
www.wired.com/story/fbi-google-geofence-warrant-january-6/
h/t 16 Blocks