Well, you never know what's going on with these people. Maybe the guy caught his wife cheating with some cyclist (and why wouldn't she?) and is taking his anger out on you. You should always get the plate number and make a record of the incident. You never know - this guy might actually hit a cyclist and you can then be a witness like with the California doctor who got convicted because other cyclists had complained about the guy before.

If you feel you must shout at them shout their license plate number. Oddly enough this usually shuts them up since they then realize they have lost their anonymity.