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.
