Even Google cant penetrate this firewall
Tiananmen Square massacre, Dalai Lama, Taiwanese Independence, Falun Gong, Dongzhou - These are just some of the words or phrases that can trigger pages on google search to be blocked, if you are searching from inside China i.e.
Google becomes the latest in the list of high profile companies to bow before the great firewall of China; compromises on its corporate ethics in order to base its servers inside the mainland. Here is the article from Guardian.
Postscript: On Tuesday, Google stock closed 11% above its friday closing of $399.