I had a situation a couple years ago where I was driving on a road where there were two lanes going in each direction. I was in the left lane traveling just over 60 mph (the posted limit was 55 mph), and there was a school bus (empty) in the right lane, which I was passing. When I got to the point of being about halfway along the length of the bus, SS driver comes up behind me flashing his high beams and blaring his horn.
Resisting the urge to brake-check him, I set my cruise control. Cruise control doesn't care how close the guy behind me is following. It won't be pressured to speed up and it won't slow down just to spite him. I figured that I'll just continue passing the bus, move to the right once it's safe to do so, and let him get by.
SS driver has other ideas. Just as I'm far enough in front of the bus to safely move over (I can see its headlights in my raerview mirror), SS driver whips into the right lane to try to get around me. He failed to clear the bus.
Seeing the SS driver's car spin out in my rearview, I pulled onto the left shoulder and hit my brakes. By the time I stopped and had my cell phone out, an unmarked police car that was apparently behind the SS driver had already turned on his emergency lights, so there was no need for me to call 911.