A late colleague of mine (my best man) served on the vice squad at Paddington for a while. He and his Sergeant had obtained warrants and confiscated 1,000s of Blue Movies from several seedy shops on the manor.
These were 8mm or Super 8. None of your videos or DVDs then.This was before the CPS existed so it was a police prosecution and investigation.
All the films had to be scrutinised very carefully. The criteria for what is obscene and what is not did give a frightening amount of leeway in those days (70s) and those submitted as evidence had to contain the relevant legal requirements to make them become obscene. After several weeks in a locked room taking turns to plough through the evidence the Sergeant asked to be relieved of his duties with the vice squad.What he had been viewing on a daily basis had seriously interfered with the physical side of his marriage.