Google recently developed a site for the Chinese government: google.cn
Part of this deal was that they would censor things that were 'disturbing' to the delicate sensibilities of the Chinese People.
Charles at LGF did a search of one word on the USA site and on the CN site and came up with a compelling example of what Censorship means and why we need to re-think our dealings with such a totalitarian nation.
Google Image Search for "tiananmen" -- USA
Click for full-size Image
Google Image Search for "tiananmen" -- China
Click for full-size Image
You have to get to page five before you start seeing images of the tanks.