Browns. A group of us Steeler fans went there a few years ago and as soon as we got out of the car, we immediately were yelled at (expected). But when we came back after the game, the car had the windows broken and all kinds of shit had been thrown into the car. They've also been known to tip over cars with Penn plates, etc and there are always fist fights. I guess I'd be mad too if my team was God awful and half the stadium was full of Steeler fans, but I wouldn't destroy others property.
By the way I'll be going to the Cleveland game again this year on Dec 10th, but I'll be sure to make my cousin take his car.