Lane splitters dont piss me off. I was young once, now it's their turn. Big freaking deal, let them go by and mind your own business.
I have seen lane splitters blast by and startle other drivers causing them to swerve. That is my problem with them. One did it to my father when I was a passenger in the car. One minute the biker boy was several cars back in another lane and the next blasting by my fathers window. Scared my father so bad we almost went off the road. I have seen this a few times.
Just because you are on two wheels does not give you the right to ignore common courtesy any more then the people in cars have the right to ignore your safety.