License-plate cameras spark privacy concerns

License plate-capturing cameras that keep track of drivers coming in and out of New York City are also popular with law enforcement agencies around the country, according to a report from the ACLU released Wednesday.

The report raises privacy concerns about the data collected from surveillance cameras mounted on police car dashboards and in key public areas. These cameras are used to combat crime and nab suspects. Similar to the NYPD, law enforcement agencies can store the data -- containing license plate numbers and the time, date and location of cars captured on camera-for various lengths of time.

"The NYPD's use of license plate readers raises serious privacy concerns," said Donna Lieberman, executive director of the New York Civil Liberties Union, in a statement. "The current system allows police to track people's movements throughout the city."

Lieberman said the NYPD needs to be under "clear regulations" to prevent the data from being used to track innocent New Yorkers.

"They should require that police have reasonable suspicion that a crime has occurred before examining the data," she said. "They should be deleted within days or weeks at most, unless there are legitimate reasons to retain records."

According to a June 21 report from Reuters on the NYPD's surveillance network, there are about 120 cameras on bridges, tunnels and traffic lights, with an additional 100 on police car hoods. The NYPD's database holds more than 16 million plates.

The NYPD did not respond to request for comment.