OK, here's my fantasy:

It's a pleasant summers day and I'm walking down my local high street. A moron, in a 'hot hatch' (if that's the right term?) stops at traffic lights. He's loudly revving a big, noisy engine and he's got his driver's window rolled down and his stereo is blaring out bass heavy 'post-music noise' at maximum volume. I search in my pockets and find that I just happen to have a tear gas grenade - fancy that! I pull the pin and toss it through the open driver's window. The moron hurls himself out of his vehicle coughing and wheezing, eyes streaming. I then find that I also happen to possess a baseball bat - or perhaps, being English, a cricket bat. I use this implement, whatever it happens to be, to belabour the moron's kneecaps with. After a suitable amount of belabouring I toss the implement over my shoulder and stroll on, a happy smile on my face.

This has been an exceptionally violent, but satisfying, fantasy!