Police across the county have made heavy use of “Fog Reveal,” a cellphone tracking tool harnessing data to track people's locations, according to a unique public account of the secretive tool by the Associated Press. Documents and emails obtained by the Electronic Frontier Foundation and shared with the AP, plus a GovSpend analysis of government spending, show that Fog Reveal sold its software in about 40 contracts to nearly two dozen agencies to create known in law enforcement as "patterns of life" that raise serious privacy concerns.
Fog Reveal has been used since 2018 in criminal investigations ranging from the murder of a nurse in Arkansas to tracing the movements of a potential suspect in the Jan. 6 Capitol riot. The tool is rarely mentioned in court records, something that defense attorneys say makes it harder for them to properly defend their clients in cases in which the technology was used. Fog Reveal was developed by two former Department of Homeland Security officials under President George W. Bush. It relies on advertising identification numbers, which Fog officials say are pulled from popular cellphone apps such as Waze, Starbucks and hundreds of others that target ads based on a person’s movements and interests, according to police emails. That information is then sold to companies like Fog. “Local law enforcement is at the front lines of trafficking and missing persons cases, yet these departments are often behind in technology adoption,” Matthew Broderick, a Fog managing partner, said in an email. “We fill a gap for underfunded and understaffed departments.” Bennett Cyphers, who led EFF’s public records work, said red flags go up when such a tool finds widespread adoption. “We’re seeing counties with less than 100,000 people where the sheriff is using this extremely high tech, extremely invasive, secretive surveillance tool to chase down local crime,” Cyphers said.