Tiananmen Square

Much has been made of the marvelous power of 'The Great Firewall of China' — the surveillance-and-censorship system put in place by Beijing's authorities on the internet. For instance, search for any of three forbidden 'T's — Tibet, Taiwan, or Tiananmen Square — in China's major search portals, such as Baidu or Google.cn, and you'll find nothing but swe…