It's the police who generally have the most up to date database and are also the only people really able to do anything with the information (other than court summons, I guess).

Regardless of who owns the ANPR, since their sole purpose (if you ignore the survelience aspect) is cutting down crime, the data will end up with the state eventually.

They all feed into the National ANPR Data Centre:

www.npcc.police.uk/FreedomofInformation/ANPR.aspx

https://en.wikipedia.org/wiki/Automatic_number_plate_recogni...