By GARANCE BURKE and JASON DEAREN
Local law enforcement agencies from suburban Southern California to rural North Carolina have been using an obscure cellphone tracking tool, at times without search warrants, that gives them the power to follow people’s movements months back in time, according to public records and internal emails obtained by The Associated Press.
Police have used “Fog Reveal” to search hundreds of billions of records from 250 million mobile devices, and harnessed the data to create location analyses known among law enforcement as “patterns of life,” according to thousands of pages of records about the company.
Sold by Virginia-based Fog Data Science LLC, Fog Reveal has been used since at least 2018 in criminal investigations ranging from the murder of a nurse in Arkansas to tracing the movements of a potential participant in the Jan. 6 insurrection at the Capitol. The tool is rarely, if ever, 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.
The company was developed by two former high-ranking Department of Homeland Security officials under former President George W. Bush. It relies on advertising identification numbers, which Fog officials say are culled 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.
“It’s sort of a mass surveillance program on a budget,” said Bennett Cyphers, a special adviser at the Electronic Frontier Foundation, a digital privacy rights advocacy group.
This story, supported by the Pulitzer Center on Crisis Reporting, is part of an ongoing Associated Press series, “Tracked,” that investigates the power and consequences of decisions driven by algorithms on people’s everyday lives.
The documents and emails were obtained by EFF through Freedom of Information Act requests. The group shared the files with The AP, which independently found that Fog sold its software in about 40 contracts to nearly two dozen agencies, according