For what it's worth, the FBI isn't the only entity keeping tabs on cellphones around the Capitol. The place is probably one of the more heavily surveilled spots

For what it's worth, the FBI isn't the only entity keeping tabs on cellphones around the Capitol. The place is probably one of the more heavily surveilled spots on the planet: https://gizmodo.com/israel-allegedly-installed-stingray-devices-around-d-c-1838061036 https://gizmodo.com/israel-allegedly-installed-stingray-devi... It will be interesting to learn how the FBI got this information, if the story is true. The government has been brushed back on requests for geofence warrants before: https://www.eff.org/deeplinks/2020/08/new-federal-court-rulings-find-geofence-warrants-unconstitutional-0 https://www.eff.org/deeplinks/2020/08/new-federal-court-ruli... That said, if a phone pinged from inside the Capitol during the riot, that seems like it could be probable cause in and of itself. Most phones that pinged that day inside the Capitol were being carried by people committing criminal trespass sort of by definition. It's almost a perfect argument for a geofence warrant.