Lenk said: Cyclists - if someone cuts you up, punching their side window fairly hard usually wakes them up. It might mean you get chased about a mile through Southwark by an irate Australian as happened to me once, but it was quite fun in retrospect. Just wanted to share that a friend of mine got cut uo by a white van man so she swore at him (not even window punching or wing-mirror breaking!) and he chased her for a long time until eventually, up a side street, he deliberately knocked her off her bike and left her in the gutter. She suffered a serious leg injury as a result. The police didn't even follow it up. Really don't advise you do it!