I don;t think it's environmentalists in big SUVs

I think when it comes to driving, some people are just plain jerks.
Don't like anyone in front, don't like to be passed.
I got fed up and passed someone on the other side of the (empty) road who was doing 30 in a 45 since I almost got rear ended by a person coming around the bend behind us.
Guy was cursing me out, didn't think he was dangerous doing 15 below the speed limit.
He did have quite a few dents in the back of the car, sure he thought he was not the cause, it's those stupid people doing close to the speed limit!