Welcome to WebmasterWorld Guest from 126.96.36.199
Nominet were instructed by the police to take down these domains and carried out the shut down.
However I think the exercise is about cleaning up .co.uk namespace so that it can have a trusted reputation with UK consumers. It was discussed at the recent Nominet registrars conference and representitives of the UK Police were speaking in panel discussions.
See DEB Impact Assessment [interactive.bis.gov.uk]