ANPR amounts to mass surveillance of the entire motoring population, no matter how innocent any motorist may be. In a free society this is unacceptable.
There are around 10,000 Automatic Number Plate Recognition cameras on British roads, they are run by ACPO, and a central database stores vehicles' movements for 2 years. No law governs their installation or use.
ANPR should be regulated. Mobile ANPR cameras should be permitted as part of police operations. Static cameras should normally not be permitted except where they serve a dual purpose (eg. London congestion charge cameras). Records on vehicles where there is no reasonable suspicion of crime should be deleted immediately (again unless there is a dual purpose, when data retention would not be by the police). ANPR for policing purposes should be operated by the police, or by some other body that is subject to proper oversight.