On November 19, 2012, state-sponsored Caijing Magazine published an article on its English language website entitled "Will Baidu Have a New Decision Maker?" at this URL: http://english.caijing.com.cn/2012-11-19/112293169.html
This screenshot shows that by November 21 anyone attempting to access the article at that URL was being redirected to Caijing's home page.
This screenshot, taken on November 19, shows that Baidu's Tieba would not allow users to establish a forum with the name "Ma Dongmin" (马东敏 - the name of Baidu founder Robin Li's wife), telling users "Apologies, in accordance with relevant laws, regulations, and policies, this bar cannot be opened" (抱歉,根据相关法律法规和政策,本吧暂不开放。)
This screenshot, taken on November 19, shows that a search on Sina Weibo for "Robin Li Divorce" (李彦宏 离婚) returns no results, just a notice saying "In accordance with relevant laws, regulations, and policies, search results for 'Li Yanhong Divorce' have not been displayed" (根据相关法律法规和政策,“李彦宏 离婚”搜索结果未予显示。)
Finally, these screenshots show that, at some time between November 19 and 20, Sina Weibo began censoring searches for "Ma Dongmin Divorce" (马东敏 离婚).