YouTube has been blocked in China for a second time, a year after the first. That time, the cause was videos of Chinese police beating up Tibetan protestors, but YouTube says it has no idea what the cause is this time. “YouTube has been blocked in China since yesterday,” confirms a spokesperson. “We do not know the reason for the blockage, and we’re working as quickly as possible to restore access to our users in China.” We’ll take a wild guess and say the cause probably isn’t music licensing rights. Although only probably.