Ben – People often attribute website blocking to China’s great firewall, as if the country had a barrier that can prevent content the government finds objectionable from getting on the Chinese Internet pipes. But that isn’t the case.
Some, but not all, of the routers in China have special software that scans for banned words. The result is that Web sites containing banned words are often not blocked until they reach the third or fourth router. Twenty-eight percent of Web sites containing words on the blacklist actually reached their destination. Link.