ANPR (Automatic Number Plate Recognition) cameras are being used to create a "24x7 national vehicle movement database" that will log the movement of every vehicle on the United Kingdom's roads. Your every move will be retained in the system for two years.
Besides "denying criminals the use of the roads", the system will also link to other databases to identify vehicles that are unregistered and untaxed. The system will be used in the war on terror; UK police have lobbied for detention periods of up to 90 days without charges for terror suspects. Once police have a tip or a suspect in custody, they can sift records of vehicle movement along with everything else.
(This Science Fiction in the News story used with permission from Technovelgy.com