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Filings in the case against suspect David Rhine show Google identified 5,723 devices as being in or near the building, Wired reported. Google in May 2021 provided names, details, and maps for 1,535 devices to the FBI. The warrants for user data are sealed, but an effort by Rhine's attorney to throw out location data showed the extent of the information sharing.

Google's sharing of cellphone information is the tech giant's largest-ever disclosure of geolocation data to law enforcement agencies. Some legal experts warn the move is a dangerous precedent for civil liberties. American University law professor Andrew Ferguson told Wired:
"The January 6 cases are going to be used to build a doctrine that will essentially enable police to find almost anyone with a cellphone or a smart device in ways that we, as a society, haven't quite grasped yet."
He added that the move could expose journalists and political dissenters to government surveillance.

Google used a three-step process in narrowing down devices to hand to federal agents, Wired reported:

In the first and broadest step, the FBI asked Google to identify all devices in a four-acre area, including the Capitol and its immediate surroundings, between 2 pm and 6:30 pm on January 6. Google initially found 5,653 active devices that "were or could have been" within the geofence at that time. ...

In the second step, the FBI asked Google for a list of devices that were present at the Capitol from 12 pm to 12:15 pm on January 6, and from 9 pm to 9:15 pm. As there were no rioters in the Capitol during those times, these devices likely belonged to congressional members or staff, police, and other people authorized to be there. Over 200 such phones were excluded ...

For the final step, the government sought subscriber information, including phone numbers, Google accounts, and email addresses, for two groups of users.

Nearly 50 cases surrounding the events on Jan. 6 include location data from Google.

Rhine's attorneys are arguing the information was collected too broadly and "almost always involves intrusion into constitutionally protected areas."