Parvipica - Managing to remember a whole plate number is impressive, well done! I've tried to do it a number of times and just failed. After about 10 seconds if I still have one or two digits, I'm lucky. I can't even remember my own plate 
I think it was from the story of an off duty cop who was a cyclist and got severely harassed on the road and actually managed to call it in and they stopped the guy (epic story, don't remember what the thread was that shared it)...
Anyway, I heard that a plate, while better than nothing, is not as good as a plate plus a description of the driver (which is almost impossible to get - that's what the cop in the above story said was most of the problem with incidents like harassment or hit and runs with bikes - no description of the human actor, no dice).
Just interesting that we have to rely on our memories during an incredibly stressful, adrenaline infused situation when they're bound to function the least. If we had cameras everywhere like some other countries, is it easier? Anybody have any London experience or similar places where big brother records what happens? I could see the man power needs balancing out the opportunities lost, but I don't know. Just curious, not wanting to start a red light camera flame war.