It seems as if China is blocking Twitter as well as Microsoft’s new search engine Bing. Other blocked sites is WordPress.com, YouTube, Flickr, Hotmail and several others. Ryan McLaughlin blogs from China and thinks the block is due to the anniversary of the Tiananmen Square Massacre on June 4.
I can only predict the next few days will see more and more sites being blocked, hopefully with things returning to normal shortly after (though if past blocks are anything to go by, it could be weeks or months).
Hat tip: Mashable