ACLU wants to know how license plate data is used

American Civil Liberties Union affiliates in 35 states are asking police and state agencies to better explain how they use automatic license plate readers.

The ACLU of Maryland says the state has reported more than 320 license plate readers in use. The ACLU says the data is potentially stored indefinitely after it is gathered from cameras mounted on patrol cars or along roads.

David Rocah, a staff attorney for the ACLU of Maryland, says the organization does not object to the technology's use to instantly compare license plates with information in other databases. However, he says indefinite storage raises privacy concerns.

The ACLU say while there is growing use of the technology around the nation, little is known about how long the data is stored.