He was offered to undergo "re-education." You might not like this meme. You might find it offensive. But should he be arrested by several officers for it? Of course not. This is just one example of many people being being arrested and imprisoned for offending people. It is against the law to offend people in the UK.
Re-read what you just linked. In the response from the JIMU:
"A 51-year-old man from Aldershot was arrested on suspicion of sending by public communication network an offensive, indecent, obscene, menacing message or matter."
This is the legal basis for the arrest. Without the retweet, police would not have had authority to turn up to his place of residence - twice - and demand entry. No doubt they preferred Brady voluntarily submit himself for interview at the station, but he refused, which I hope we can all agree is the morally correct position. No one should have police turn up outside their house - TWICE - because of a parody retweet.
The law might be a bad one (and probably is) but on balance better that police investigate suspected illegality than don’t. Overall I’d rather be somewhere where even a former royal can be arrested than somewhere the rule of law is optional.
Haha, any comments on that? The police didn't even apologize or admit a mistake, they believed they were doing the right thing and just made a waffle statement about "reflects need in our local communities."
Police make mistakes, in some countries they arrest someone trying to incite an arrest and that's bad. In some countries they shoot someone for driving 5mph over the limit, that's worse. The police in the UK do far worse than wrongful arrests so while bad, it's not really on my "top ten problems" list.
https://www.whatdotheyknow.com/request/arrest_of_mr_darren_b...
This is why the Daily Mail causes rolled eyes (along with Spiked and the rest of the right-wing agitprop).