Yeah, I was watching some youtubes about this last night. Not just the UK, it's going on all over america.
There was one guy who started getting views staging this evil clown encounters, but now people are freelancing it, some of them carrying bats and machetes and chasing down unsuspecting passerbys. They just stay in some rural spot waiting for their victims. Hasn't been a murder yet, but there is one video where these dudes spot the armed clown in the middle of a rural road at night, blocking their way and they get out of the car and beat the living fuck out of him.
I mean, technically, cosplay is perfectly legal. But hanging out, especially with weapons, and engaging unsuspecting victims falls under harassment if not assuault... or some other criminal charge, gotta be, right? You're the laywer, so give us your take.
For my part, some evil clown jumps on your car or pops out at you from an alley and you beat him to living fuck, that's called self-defense.