When it's just you and the other car on the road, there's no way of proving what happened, you just have to hope there were witnesses, or god forbid you do get run off the road, that the accident scene has enough evidence to show criminal intent.
Yes, there's probably giant privacy implications there, but fuck it. They're trying to kill people out there.
Showing this kind of behavior could prompt their insurance to drop them or possibly increase their premium.
Most cars are blocked by other cars on the road and you don't see cars honking at other cars nearly as often as it happens to bicyclists (except maybe in NYC... hehe)
Also, most of the time the substandard width lane issue is only a factor within cities. Cars shouldn't really be traveling that quickly within a city, except maybe on elevated highways.
Every cyclist should go out and measure a lane or two here and there to get a feeling for approximately how wide a 14 ft lane is, so you know when you can legally take up the whole lane.
The only other thing to keep in mind with this, is that if you do take up the whole lane, it is your responsibility to pull over to the right periodically if the number of cars backed up behind you exceeds 5 (IIRC)