When sport fans go to crazy if can danger like jail, death and ect. In 14th century England a group of fans at a footbul (soccer) game go so out of control, later after the game the King banned soccer. That is not it,
in Argentina when they lost to Germany in the World Cup Finals they got out of control too, cops had use tear gas, and rubber bullets too. In Argentina that is not the first incident, much earlier a soccer team lost and the fans decided they wanted to overthrow the emperor and in the time they burned down the village, sadly that lead to 30,000 deaths that day. Sports fans just getting over excited can cause lots of things and most of them are bad, is it really worth a sports game to kill thousands of people.
Fans getting overhand does not just cause danger but it can cause mental issues too. Psychologists believe that fans go crazy because of the history behind it, Centuries ago tribes would get excited because of the tribe warrior fights and they believe it carried on to the sports now and how the fans act. But the effects of that can lead to bad things mentally. It is always fun to watch your sport team win, but no team can win them all. Losing can cross the edge for people. People have been becoming depressed, skipping school and work. Sadly there have even been recordings of suicide.
Others might say that when you're a fan and the team wins it makes them feel good, On the other hand it can make people distressed when they lose. Just because people get out of hand, lives are taken away and ruined, it is not worth it. Think about a time a team lost and what could have happened to the fans at the time, it could have lead to danger or maybe death. Other that danger, losing can cause mental/emotional problems too. Go to a sports game and watch the fans when someone scores a goal on the favorite team, or a touchdown in the last seconds, they are happy or sad and on the 50% chance of being sad, it might ruin one of those fans life just because they went too far in cheering and got caught in the action. Millions of people are being killed at sports games if not after that, like the boston marathon, people died, it is important that something changes because people are dying and are getting mental problems.