The answer is not always but rather at sporting events. Stay with me here. This is not a white and black issue. This is a home and away issue. It is rather annoying to spend your time and money to go to a home game only to find that someone in your section has "sold out" and given their tickets to an away fan. This can ruin your game experience when the away supporter is boisterous about his team and yours is losing. When you travel to an away game you know what your getting into. However if you go to an Eagles game at the Linc, you don't expect to be sitting next to a Cowboys fan. Nor should you have to. It happens though and far too often.
Fights break out, visiting fans minding their own business are abused, beer is poured on little kids, and 13 year old girls are called sluts. This is not ok. Drunk or not. I propose that a percentage of tickets are made for away fans and away fans only. Set aside a couple of sections for the away fans and have them passionately root for their team. No home team colors are allowed in the section and no away team colors are allowed outside the section. Prepare a separate entrance and concourse for the away fans and surround them with security. This will limit the amount of incidents at games and make the experience better for home and away fans.
For those who don't want to be segregated to one section you can sit amongst the masses if you can behave. You cannot wear away colors, You will keep you mouth shut when the away team scores and you will not start any trouble or your gone.
Nearly this whole concept is taken from my experience in London where opposing fans have separate entrances and exits. It's also based on my experiences in sitting in away seats where I've had alot more fun cheering with my fans despite my seats being worse because of it. I've also been to home games and sat next to opposing fans and if they didn't trash talk it was real annoying sitting near them while they cheered against you. I would never invite a Duke Fan to my house to watch a game no matter how much I liked the guy.