The American Civil Liberties Union of Pennsylvania sent requests Monday to more than a dozen local police departments for information about how they use automatic license plate readers.
The requests under the state's Right to Know Law were part of a coordinated effort by the ACLU in 38 states to compile data on the cameras, which snap photos of plates.
The ACLU also filed Freedom of Information Act requests with the departments of Justice, Homeland Security and Transportation for information on how the federal government funds and uses the technology.
The civil rights organization is worried about how police are using the license information and how long they store it.
"We're concerned with the data for law-abiding citizens," said Sara Rose of the ACLU in Pittsburgh. "It's just what we see going on everywhere, with collections of personal information in giant databases and no rules on how it will be used."
License readers are mounted on patrol cars or along roads on poles and bridges. They take photos of every license plate that enters their view, stamp it with a time and date and send it to a database that automatically alerts police whenever a match appears.
Police say it's a good tool to catch criminals and the ACLU agrees, but the technology also makes it possible for police to track anyone who drives.
The organization said it wants to make sure police are using the cameras in a "limited and responsible" manner.
"Police departments nationwide are using [license readers] to quietly accumulate millions of plate records, storing them in backend databases," the ACLU said on its website. "While we don't know the full extent of this problem, we know that responsible deletion of data is the exception, not the norm."
Many local departments are using the camera systems, often with funding from federal and state agencies.
In addition to the police agencies, including the state police and the Pittsburgh and Philadelphia departments, the ACLU submitted requests to the Port of Pittsburgh Commission and the Pennsylvania Auto Theft Prevention Authority, which have given money to local police for cameras.
The Right to Know requests ask police for details on how cameras are used to track motorists, including how long the data are stored and who has access to the data.
The ACLU said it selected the police departments based largely on media reports about their camera systems.
Besides the Philadelphia and Pittsburgh police and the parking authorities in each city, they are: the Washington County sheriff's office and police in Peters, North Strabane, South Strabane, Cecil, Canonsburg, Monaca, Baldwin Borough, Baldwin Township, Mt. Lebanon, Edgewood, Swissvale and Homestead.