Re: "there is no criminal offence of watching videos"
Many years ago I was questioned by two plain clothes policemen for several minutes who were waiting for me outside my hotel. They were arguing my Range Rover's tax disc was invalid because it stated the make as "Land Rover". My subsequent query to DVLA was answered with "Land Rover". Since then I have seen the same bloody-minded attitude used to prosecute innocent people in more serious cases.
An ex-police officer privately advised that in those situations it was well known that some officers were "hard men". Worse it was also a reputation worn with pride by whole police units. They decided who was guilty - then pursued that assumption by any means possible. Complaints from arrested, but not charged, law-abiding people were discouraged by veiled threats of "anonymous" smears in the local media or future harassment. Defence witnesses were also threatened, off the record, with "consequences" - if they didn't change their statements to incriminate the defendants. Nothing provable of course. The worst thing was that the institutions then closed ranks to excuse such officers as being "zealous".