Most cagers I have had issues with are oblivious that they did anything wrong.... They just did not see me. I really can't get mad at them, its just a fact of life. If I was angry at every stupid minivan or SUV, I would not be able to enjoy motorcycles.
Only time I take issue is with pricks in sportscars that loose face since their $50,000 corvette just lost a stoplight race to a $7000 motorcycle.
Had one case where my wife blew away a tony in a camaro (with donna in the passenger side) on a yamaha seca II of all things. He decided to save face, and prevent any further shrinking of his penis (just got whooped by a girl) it would be funny to try to run her off the road.. So I got between them, and kept slowing down to about 10 mph.. my wife sped away, he got angrier, and angrier, and kept reving his engine and rushing my bike... he almost hit my back tire a couple of times. I wanted to block him from taking off, get him to stop, and beat the ever living **** out of him, but he kept trying to gun it and pass me when ever he got a chance.
Eventually, I got some brains, let it go, and just blew him away, a very easy task on any motorcycle.
I was actually pretty pissed at myself later for taking that risk, and for giving into that anger. It clouded my judgement, and could have been a disaster if that kid actually was crazy enough to make contact with my bike (theres plenty out there.)
Being in a cage or on a bike, everything gets very anonymous. It makes it easier to get angry at "the person driving that car" than the actual person. I doubt many of us would be as angry or as ready to "kick someones ass" if we were face to face with the person, not just staring at the car.
However, catharsis does feel good, and banging on windows of minivans and SUV's that are coming into my lane is sometimes startling enough to make the stupid bitch drop her cellphone.