Via Daily Mail:
More than 500 teens flash mobbed police who came to disperse them during an unauthorized cookout at a Philadelphia recreation center.
The mob occurred in Philadelphia’s Germantown neighborhood on Sunday night, outside the city-run Lonnie Young Recreation Center.
Police said that the incident began at around 9.30pm, when officers arrived to find the center’s sidewalks and street filled with teenagers, believed to be age 12 to 17.
The teens refused to go home and officers at the scene said that bottles were thrown at them as they tried to get the crowd to disperse, according to CBS Philly.
Videos posted on Facebook and taken by cookout attendees showed that teens also climbed on top of cars and blocked siren-blaring cop cruisers by taunting and dancing in front of them.