How does Google censor?
From what little you can see from the outside, it seems Google censors based on domains, sub-domains, full URLs, or keywords. For example, all of the roughly 2.25 million pages of news.bbc.co.uk are censored in Google China web search, hinting at a URL blacklist. In Google image search China, the keywords “胡锦涛” (Chinese president Hu Jintao) or “六四” (colloquial Chinese for the Tiananmen Square Massacre) are fully censored, hinting at a keyword-blacklist.
