License plate scanners have become a fact of life, attached to traffic lights, police cars, and elsewhere, says NPR. All those devices have created a torrent of data, raising new concerns about how it’s being stored and analyzed. Bryce Newell, a PhD student at the University of Washington who studies surveillance, says, “As we mix data between roving systems on these patrol cars and systems mounted on, say red lights, law enforcement could get a much better picture of our individual movements, and with enough data, [police can] predict when we might leave our home and when we might be at home, for instance.” With millions of scans, patterns emerge and unusual activity stands out. The Colorado Bureau of Investigation has analyzed license plate scans from an area near where a murder victim was found. Director Ron Sloan says it’s a promising technique, but it’s one he fears police will lose because of privacy fears. He and several other heads of police associations sent Congress a letter warning that public “misconceptions” may end up restricting police use of license plate data.
States keep passing new restrictions on how long police may store license plate data. Under these laws, police have only a few months before they have to hit delete. Still in the long run, these state laws may be moot because even as states limit the size of police databases, private ones keep growing. Jennifer Lynch of the Electronic Frontier Foundation says the nation’s biggest collections of license plate data are in private hands, controlled by companies such as “Vigilant Solutions.” Their information is basically unregulated. “Private companies don’t have the same responsibilities as government,” she says. “Vigilant doesn’t have to provide any transparency to the public about how it collects the data, how long it retains it for and who it shares it with.”