Football is the most watched sport in all of the world. It is also the most passionately supported.
However, with that passionate love of the game comes a great price. At the worst of times that price is even paid in the form of life.
Football is the one sport that has more violence-related fan injuries or deaths than any other. Unfortunately, that has become an all-too-common occurrence in the game around the world.
Ultra fan groups turn the love of competition embraced in the game into something completely different, and many times violence is the outcome between rival club gangs.
In looking at the effect of violence on the game, we take a look at the 10 most dangerous fan bases around the world.