It's funny that so many BYU fans still play the "beer" card after Max Hall's comments. It just shows such a willingness to fall in line with whatever they've been told. As YB already mentioned, beer is not sold at RES and like YB, I have never seen anybody successfully sneak it in. Nevermind the fact that Max Hall flat-out lied about the beer incident (classy move btw), let's just go ahead and keep assuming that sort of stuff happens. Anytime BYU has won @ Utah, I've never seen news reports of beatings or any other serious conflicts. The fact of the matter is, BYU fans have been attending games @ RES for years, rooting on their team, and going home safely afterwards.
General rule of thumb: If you're going to wear opposing teams gear into an away stadium, be ready to take your lumps. While nobody deserves to be physically assaulted, you shouldn't get a free pass either.