China likes to aggressively censor pretty much everything that even remotely criticizes the party or its history.

"A Chinese star TV anchor is facing "severe punishment" over jokes he made about Mao Zedong, state media report. A video of Bi Fujian singing a parody song at a private banquet and insulting the former Chinese leader in strong language was posted online in April."

http://www.bbc.com/news/world-asia-china-33844095