Please report dangerous drivers to the police - Roadsafe. Report to plod, not just whinge here.

Wow indeed.

i agree that in a town or busy traffic lifesaver is a must. if i am overtaken by impatient car driver in a dangerous way, i usually chase after him/her, get in front of (usually after first/second set of traffic lights) and then position myself in the middle of the lane so i cannot be passed. if driver starts arguing, i politely (that depends on the situation really) explain why i am doing it- i just hope that next time they will think twice before make any risky manoeuvre

So you've just discovered a bad/dangerous/reckless/impatient driver, so you chase after them, and place yourself right infront of them?! U mad?

Best possible course of action is to do your best to stay calm and carry on cycling and concentrating on the road ahead of you. You certainly won't be teaching a driver like that ANYTHING by antagonizing them. All you've done there is possibly pissed them off further and put yourself at risk.