Isn't it just road rage though..? except for the fact that you are already 'out of your car' so to speak and banging on their window..
Cyclists are roundly despised enough by motorists as it is, without a mob of snotty know it all vigilantes getting all irate and waving their bicycle clips at anyone they perceive to be driving outside of the highway code..
Like I said, I do it myself, but it can't be a positive thing surely..?
Maybe cyclists should be granted special police powers..?