They’re called automatic license plate readers.
And they’re used by police and state agencies.
But the American Civil Liberties Union of Maryland has joined affiliates from 35 other states who want a better explanation from authorities on how the information is used.
The ACLU of Maryland says the state has reported more than 320 license plate readers in use.
The civil liberties organization says the data is potentially stored indefinitely after it is gathered from cameras mounted on patrol cars or stationary objects along roads.
David Rocah, a staff attorney for the ACLU of Maryland, says his organization does not object to the technology's use to instantly compare license plates with information in other databases.
But he says he is concern about the indefinite storage.
The ACLU says while there is growing use of the technology around the nation, little is known about how long the data is stored