Foxconn shuts one of its Chinese factories after a dormitory brawl escalates into a violent riot involving maybe 2K workers. About 79K work at the Tiayuan plant, which may make the back plate for the new iPhone 5. However, others say Apple has little exposure there. Foxconn falls 2.6% in Hong Kong. Parent Hon Hai falls 1% in Taiwan. AAPL -0.7% premarket.