Fog Reveal allows police to see cellphone location data that was initially collected by smartphone apps. Officers can sweep an area to see which phones were in a particular location at a given time. They can then use that information to see a 90-day “pattern of activity” that shows where a device traveled, according to a user manual published by Vice News.
The software uses data collected by apps that’s sold to digital data brokers. From there, the data can end up in the hands of a range of clients, including advertisers, the military, health insurance companies and law enforcement.
VSP and Loudoun County-based Fog Data Science maintain that the data is anonymous and isn’t tied to specific people. But Adam Schwartz, a senior attorney at the digital privacy nonprofit Electronic Frontier Foundation, said it’s “child’s play” for police to figure out the identity of any given cellphone user based on their unique “pattern of life,” including the places they live, sleep and work.
Schwartz acknowledged there is investigative value in law enforcement having access to people’s location data, but questioned “who gets to decide when the police use this tool?”
“The position at the EFF is that it should be a judge deciding whether there’s probable cause of a crime and deciding whether to issue a warrant,” Schwartz said in an interview.
In an email, VSP spokesperson Corinne Geller characterized Fog Reveal as a “tool of last resort” that’s been used in “about 18 criminal investigations.” She said VSP hadn’t requested a warrant in those uses because it hadn’t needed to identify a mobile device owner. Geller said access to the tool is limited to a handful of special agents and supervisors in VSP’s high-tech crimes division. A governing policy its use is currently “waiting for final approval by executive leadership.”
More specifically, Geller said the tool was used after a hit-and-run incident where someone on a scooter was killed; there weren’t witnesses or surveillance cameras to capture the crime or evidence from the vehicle at the crime scene. And so officers turned to Fog Reveal. It didn’t yield any leads and the crime remains unsolved, Geller said, noting that the software “has yet to generate any successful investigative leads or evidence” in any VSP case.
Jessica Tocco, a spokesperson for Fog Data Science, said in an interview that the tool was not meant to be “the end all be all” for crime fighting and compared it to a camera on a street corner. Tocco said that law enforcement still needs a warrant to connect an Ad ID to a specific person.
Tocco said that a feature showing a device’s location for a 90-day period required “probable cause and justification,” with access determined by “internal protocol, laws, and regulations.” But she couldn’t point to anything in the product itself to prevent law enforcement from freely using the feature.
“I would say to this any tool — a gun, a camera, running a license plate can all be misused by law enforcement [and] I would not single out our product,” Tocco said in a text message.
Matt Callahan, a senior staff attorney at the ACLU of Virginia, characterized Fog Reveal as an “invasive surveillance technology” and said few people who download apps realize their location data might wind up in the hands of police.
He argued that using the tool could be a violation of the Fourth Amendment, which protects against unreasonable searches.
“At a minimum, before any new technology is adopted by law enforcement, the decision to use it should be subjected to an open and robust debate with the public,” Callahan said in an email. “That conversation has not happened with the use of Fog Reveal in Virginia.”
Schwartz, the EFF attorney, said smartphone users should practice “surveillance self-defense” by disabling AD ID trackers — the ad identifier tied to your device — and being careful about what apps they download. But he said those steps weren’t enough on their own and called on lawmakers in state legislatures and Congress to ban police warrantless use of the service.