Via the New York Times:
SHANGHAI — Foxconn Technology, a major supplier to some of the world’s electronics giants, including Apple, said it had closed one of its large Chinese plants Monday after the police were called in to break up a fight among factory employees...
A spokesman said some people had been hurt and detained by the police after the disturbance escalated into a riot late Sunday. The company said the cause of the disturbance was still under investigation.
One Foxconn employee reached by telephone Monday afternoon, however, said the disturbance had begun when workers started brawling with security guards, and it eventually had led to a huge riot involving more than 1,000 workers.
And from YouTube, "Foxconn Worker Riot, Taiyuan Plant - 9/24/2012." It's mostly large crowds of people walking around in the dark, sometimes shouting. But if the video is legit, even this would be a significant departure from what's reportedly the norm at Foxconn: