By now, you've probably noticed the license plate readers mounted on police cars. They're cameras, usually on the rear fenders of the police car, giving them a clear view of the license plates of cars in adjacent lanes.
Initially, the devices were used mostly to check against lists of stolen cars, those registered to wanted persons and, perhaps, parking ticket scofflaws.
But increasingly, the American Civil Liberties Union (ACLU) says, the data gathered by the cameras is being fed into massive databases that contain the location information of many millions of innocent Americans stretching back for months or even years.
"This is what we have found after analyzing more than 26,000 pages of documents from police departments in cities and towns across the country, obtained through freedom of information requests by ACLU affiliates in 38 states and Washington, D.C.," the ACLU said in a statement. "License plate readers are just one example of a disturbing phenomenon: the government is increasingly using new technology to collect information about all of us, all the time, and to store it forever – providing a complete record of our lives for it to access at will."
The ACLU has published a report on its findings is now releasing all of the documents it has gathered and making it available through an interactive map, so that citizens can see what information their local police department has on them.
Some uses are beneficial
The ACLU concedes that there are no doubt beneficial uses of the technology.
"We don’t object when they’re used to identify people who are driving stolen cars or are subject to an arrest warrant. But they should not become tools for tracking where each of us has driven," the civil-liberties group said.
But since the cameras take photos of every passing car, they gather information on people who are completely innocent, as this sample data from the ACLU studies show:
While one or two photos don't amount to much, over time the government is collecting a massive amount of information about Americans as they go about their daily chores. It would not be hard to imagine scenarios in which this data could be used improperly.
"The government doesn’t have a great track record of using this kind of information responsibly," the ACLU said in its report. "[T]he data can be abused for official purposes, like spying on protesters merely because they are exercising their constitutionally protected right to petition the government, or unofficial ones, like tracking an ex-spouse."
Limit retention time
What's the solution? The ACLU suggests that data not be saved unless it generates a "hit." In other words, if a license plate number is on a "hot list," any sighting of that plate should be retained while all other data should be promptly discarded.
"There is no need to store plates for months or years," ACLU argued.