I know of one person pulled over for hogging the left lane and have seen a truck pulled over for it.
Generally I’ll flash my lights if the person is not over taking the traffic to the right. If they are over taking the other traffic, but by only a very minor degree, then I hang back and wait.
What I really, really hate is being on a 2 lane highway on my motorcycle with a truck in the right lane and a car either keeping pace or very slowly overtaking it on the left. I can not stand being anywhere near a large tractor trailer on my bike and would really appreciate being able to pass it quickly.