This is an interesting piece via David McCandless's information is beautiful via the guardian newspaper

After Google announced it may stop censoring the internet in China, I became curious about what exactly that meant. What kind of censoring are they doing? How extensive is it? What can and can't you do online in the People's Republic. What does China censor online?

Broadly speaking, most of the big social websites - Facebook, Twitter, YouTube - are all blocked. Many familiar sites, such as Wikipedia, remain but with entire sections or contentious pages disappeared by The Great Firewall. Porn is pretty much outlawed.

Data in this area is difficult to come by. is a good source but most of the information dates back to 2008. Censored search terms and online materials often vary from region to region. Sites are routinely blocked and then unblocked, sometimes on a weekly basis. You can check it for yourself in this Google Doc. More...