Anth - actually yeah. When can we expect to see a scheme like the Met's Roadsafe (IIRC) where you can report antisocial driving and they get in touch with the perp? It's been quite popular down there.
re: the digression into 'undertaking' and 'overtaking'. Personally, I think passing traffic that is indicating to go to the same side is extremely unwise. However, I will pass traffic if I judge it safe to do so on either side. I think it's fair to say that drivers have a responsibility to check that they aren't about to nail a cyclist just in the same way that cyclists have a responsibility not to put them in that position gratuitously.
Or, in shorter form: cyclists shouldn't pass left-turning HGVs on the left. Does that mean if an HGV driver sees a cyclist coming up the inside they're allowed to crush them? Or that they can get away with not checking their mirror at all?
I got into an argument with an LB driver a few weeks ago because he failed to overtake me before he got to his stop and wanted to pull in. We were alongside for about 100m travelling around 20mph - me in the bus lane (not a cycle lane) and he in the main lane. He insisted I was undertaking him, but from my point of view, he should have dropped back. Small consolation if I hadn't managed to chicken him out though, or he wasn't paying attention.