The American Civil Liberties Union of Maryland joined with ACLU affiliates in 38 states to send requests to local police departments and state agencies to seek information on how they use automatic license plate readers to track and record Americans' movements. Here in Maryland, the state has reported that there are more than 371 ALPRs being used and more than 70% are linked to the Maryland Coordination and Analysis Center, Maryland's "fusion center," where the data is aggregated and stored for one year, creating an ever-growing database of our location and travel through the state.    

ALPRs are cameras mounted on patrol cars -- or on stationary objects along roads - such as telephone poles or the underside of bridges -- that snap a photograph of every license plate that enters their field of view. Typically, each photo is time, date, and GPS-stamped, stored, and sent to a database, which provides an alert to a patrol officer whenever a match or "hit" appears when the plate is checked against external databases, such as lists of stolen vehicles.

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Maryland Public Information Requests were sent to 27 local police agencies, 4 state police agencies, and 6 other state agencies.


071713: ACLU Releases Documents on License Plate Scanners From Some 300 Police Departments Nationwide; Maryland Documents Show Over 85 Million Scan Records in 2012, and 99.8% of records are about persons not suspected of any criminal activity

073012: ACLU Seeks Details on Automatic License Plate Readers in Massive Nationwide Request; Information Sought on How Cameras are Used by Police Agencies and How Data is Stored


National ACLU website on Automatic License Plate Readers


Catherine Crump, national ACLU; David Rocah, ACLU of Maryland

Date filed

July 30, 2012