According to Forbes, Google has sent 1,494 device identifiers to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to help them investigate arsons carried out across Milwaukee, Wisconsin, throughout 2018 and 2019. “The requests, outlined in two search warrants obtained by Forbes, demanded to know which specific Google customers were located in areas covering 29,387 square meters (or 3 hectares) during a total of nine hours for the four separate incidents,” the report says. “Unbeknownst to many Google users, if they have ‘location history’ turned on, their whereabouts are stored by the tech giant in a database called SensorVault.” From the report:
To investigators, this kind of “geofence” demand is useful, allowing them to go through the data trove provided by Google, look for devices of interest such as a known suspect’s phone and ask for more personal information on the user of that mobile. But it’s also the kind of search that’s been making pro-privacy folk anxious over the last year. Such data grabs, also referred to as “reverse location searches,” see the police give Google a timeframe and an area on Google Maps within which to find every Google user within. Google then looks through its SensorVault database of user locations, taken from devices running the tech giant’s services like Google Maps or anything that requires the “location history” feature be turned on. The police then look through the list, decide which devices are of interest to the investigation and ask for subscriber information that includes more detailed data such as name, email address, when they signed up to Google services and which ones they used.
It’s unclear whether or not Google handed over any identifying information, but to Jerome Greco, a public defender in the Digital Forensics Unit of the Legal Aid Society, it’s a sign that geofence warrants are overly broad and endanger user privacy. “The number of phones identified in that area shows two key points,” he tells Forbes. “One, it demonstrates a sample of how many people’s minute-by-minute movements Google is precisely tracking. “Two, it shows the unconstitutional nature of reverse location search warrants because they inherently invade the privacy of numerous people, who everyone agrees are unconnected to the crime being investigated, for the mere possibility that it may help identify a suspect.”For what it’s worth, Forbes did obtain a search warrant that indicates Google is trying to fight back against overly broad government requests, “but still appears to be handing over innocent people’s information as well as legitimate suspect data.”