Turkish football fans have a reputation for being absolutely batsh*t mental, and this goes beyong simple passion. There is a huge hooligan element, including attacks on foreign fans and huge riots between rival supporters of the largest clubs.
This video is unlikely to quash such thoughts, as fans of Besiktas and Galatasaray were detained by police after rioting at a wheelchair basketball game between the two clubs.
The reason for meeting to riot at such and inauspicious occasion is because fans of the two clubs (and Fenerbache) are banned from attending away games between the clubs in football and basketball due to previous violence. This ban does not include wheelchair basketball, although one can assume that it now might.
Play was suspended before the end of the second quarter, and police wearing riot gear sprayed tear gas and feuding fans, forcing players to take cover and attempt to avoid breathing in the gas.