Automatic License Plate readers (ALPR) are becoming much more common. Maryland Coordination and Analysis Center has more than 320 cameras on bridges, toll booths and tunnels that scan plates and run criminal records checks on each vehicle, automatically. In addition these LPR cameras are mounted on cars.
Recently a Florida driver was detained and his vehicle searched because the Plate Reader check showed he was a Florida licensed gun owner. Article here about ALPR's- (Maryland has strict laws on transporting firearms.....but lets not get all sideways about guns)
Maryland License Plate Reader
