Gratuitous violence against a security guard in a San Francisco shopping mall

A video showing a teenage girl assaulting a security guard at San Francisco's Stonestown Galleria has gone viral on Twitter. The assault appears to be one of the latest violence to take place at the mall, which had at least three separate incidents involving minors between March 15 and 17, police said. The video shows the teenager pushing the security guard from behind against a window before repeatedly punching him to the ground. Other security guards intervene as the attacker's companions attempt to stop them. The Twitter account Asian Crime Report, which documents crime in San Francisco, relayed this fight in the mall.