A little noticed surveillance technology, designed to track the movements of every passing driver, is quickly proliferating on Maryland’s streets. License plate readers (LPRs), mounted on police cars or at fixed locations like on road signs and bridges, use small cameras to photograph thousands of plates per minute.
They might be called license plate readers, but this technology can also capture images of the car’s passengers along with other data like the date, time, and location of the picture taken. This information is than often pooled into regional sharing systems. As a result, enormous databases of innocent motorists’ information are growing rapidly and is often retained for years, with few or no restrictions to protect privacy rights.
Knowing where someone drives is one thing, but this technology could also allow someone to pin-point where an individual works, shops, worships or goes to have fun — all information that someone, even a law-abiding citizen, may not want law enforcement to have in their records.
Under Maryland law, the use of data collected by license plate readers is limited to “legitimate law enforcement purposes,” and requires law enforcement agencies to create basic minimum procedures governing access to LPR data. But the law exempts LPR data from public records act requests—including a requestor’s own data, and there are no limits on how long the data can be stored.
So how many images are being collected? In nearby Washington, DC, a Freedom of Information request found that over 200 million scan were made by DC police in 2012.
In Virginia, the state’s Supreme Court has agreed to hear a challenge over how long police can keep data from automated license plate readers. Privacy advocates warn that keeping the data beyond a short period of time amounts to “mass surveillance” and creates the possibility for abuse by police or others who can access the data, by creating a trail of personal movement.
The court’s ruling in this case could have a big impact across the country. Only 14 states have laws addressing the use of license plate readers at all, and just eight of those address how long the police can maintain the data.
“As modern technology evolves and law enforcement uses it more and more, there’s got to be checks and balances and real regard for the privacy rights of innocent citizens,” said ACLU lawyer Hope Amezquita.