Police officers look up license plate numbers to identify vehicles of suspected law breakers, track stolen cars and to collect on unpaid parking tickets. In an eight-hour patrol shift, license plate readers are capable of logging thousands of license plate numbers.
License plate numbers are unique to each vehicle. With a license plate number, police officers can obtain name and address records from the Department of Motor Vehicles, which are used to check for warrants on a driver's arrest.
As of February 2014, Homeland Security is urging for a national license plate tracking system that would be used to catch illegal fugitive immigrants. Such a system would also cut down the time it takes to conduct surveillance. There is a huge potential for abuse of the collection and storage of this kind of information, and some states are declaring this data collection illegal. The proposed database would be a file that includes the vehicle's make and model, maps and registration information, a close up image of the license plate and a zoomed-out image of the vehicle.
Repossession companies scan license plates at night so they can send in a tow truck to collect the car. Having access to such a database potentially triples the number of cars that are repossessed a night.