Safety vs. privacy: Concern over license plate readers

(CBS News) In the wake of the NSA spying scandal, a new report claims millions of license plates are being photographed by law enforcement using special cameras. According to the American Civil Liberties Union, the pictures can be kept for decades in some databases.

ACLU warns of mass tracking through license plate scanners

The readers are mounted on patrol cars, on bridges or overpasses and once they take a photo, they are able to check it against a database of suspect vehicles or individuals. They are also capable of tracking the date, time and location of where the license was photographed.

Currently, there are no federal regulations on license plate readers and it is up to the individual states how long to keep the information on record.

"This is a great tool and something we started using in the LAPD in the early 2000s," CBS News senior correspondent John Miller said on "CBS This Morning." He previously served in top positions at the New York and Los Angeles Police Departments.

"What it is, is cameras affixed to the front and sometimes the back of police cars. And every car it passes, every car that passes it, it records the license plate and then runs it automatically against data. Is the car connected to a crime? Is it wanted for murder? Is the registration suspended? And so on," clarified Miller. "So basically what it has is a thousand eyes, it has a long memory and one of its best qualities is it's color blind. When it says a car is suspicious, it's based on data."

Miller explained that this system does stop crime, and that it can find stolen cars "almost faster than any other system." He said that in Prince George's County, Md., they have a huge carjacking problem and they've been able to recover more stolen cars since they started using the license plate readers.

The county has also had more luck retrieving the cars prior to them being stripped of valuables when they use this system.

Drivers beware: More cameras scanning license plates

Miller doesn't believe that there is a privacy issue in just recording the plate numbers, because the digits are already on a car that is driven around in public, so there is a no reasonable expectation of privacy.

However, he thinks privacy issues may come into play when considering how long to keep the information in a database. A big complaint is that storing the information allows law enforcement to piece together a person's habits, but Miller said during his time in the LAPD it helped them bring in many criminals because of that.

"When we had a rash of burglaries in Bel Air, we put license plate readers in and out of the main route and then we would query the system. On the days when we had these burglaries over a period of weeks and months, the same car came only on the day of the burglary, right before the burglary and left right after," said Miller. "It gave us the leads that actually led us to the burglar. It's a powerful tool but it's going to need some standards."