Many years ago when I was at college there was an older lad that would ride a pretty naff road bike. All legal and that but not the best made or the nicest looking imo. I always remember asking him why he wore his chain and padlock into class as I'd presumed he'd need it for his bike.
He confessed it wasnt for the bike but for defence. Two cars had cut him up badly and he'd swung this thing like a mace into their rear window, probably smashing the hell out of it.
I've had a few "run ins" myself. I dont ride primary unless theres a pinch point, but I dont ride the gutter either tbh. I dont ride slow or particularly slow down traffic. Yet the way some people behave is shocking. I try never to respond with swearing or hand gestures.
I had a DHL van driver pull out on me last second 2 years back, screached on the breaks and shouted "Are you trying to kill me!?" The guy puts it in reverse and comes right at me, luckily I was turning left at that point (it was a cross roads). He's hammering on his horn shouting obscenities (at 6.45am too, so must have woken the neighbourhood).
I could go on. Loads have happened. Theres no need for it, people should just be nice and behave imo.