During a recent Chief Keef concert his fans in attendance broke out into a huge melee while he was in the middle of his performance. This clip starts out with Keep getting a new grill for himself, and then transitions into the violent occurence brought on by some unruly fans. Keef and his crew continued to perform while the fists were flying.
Source: Vladtv
http://youtu.be/t7d9W5J6alI