Tech tool offers police ‘mass surveillance on a budget’
apnews.com
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.

The data broker Fog Data Science has been selling access to what it claims are billions of location data points from over 250 million smartphones to local, state, and federal law enforcement agencies around the US.

The data comes from tech companies and cell phone towers and is collected in the Fog Reveal tool from thousands of iOS and Android apps. Crucially, access to the service is cheap, often costing local police departments less than $10,000 per year, and investigations by the Associated Press and Electronic Frontier Foundation found that law enforcement sometimes pulls location data without a warrant.

The EFF conducted its investigation through more than 100 public records requests filed over several months. “Troublingly, those records show that Fog and some law enforcement did not believe Fog’s surveillance implicated people’s Fourth Amendment rights and required authorities to get a warrant,” the EFF wrote.