I remember once when I was slow, before my VW Diesel, I was going up a hill. A truck pulled out passing the car behind me, and me, with a corner coming up. A car came around from the other direction, and the truck barely made it in, almost hitting me. Later down the road, I saw him pulled over, so kept my eye out in my rear view. Sure enough, he catches up and tries to pass me on a double yellow again. I cut over and blocked him. He tries it again and I cut over and ran him all the way into the dirt shoulder. He was pissed. I did let him pass when we came to a passing zone. He was trying to get me to pull over, but I wasn't that dumb. I am hoping he learned a lesson, though he probably didn't even remember it was me he almost hit. While it probably isn't right, I will still try to cut someone off who is trying to pass me in an unsafe area as it is much easier for both of us to get back into the correct lane than it would be if they were along side me. I even had a semi try passing me in a place there was no way he could have made it. It was a good thing I cut him off as a car came over the hill, and I know someone would have had an accident. Hopefully he messed up his load as he had to slam on his brakes.