From China Digital Space
帝都 (dìdū): imperial capital
Beijing. Often contrasted with the Demon Capital (魔都 mó dū), i.e. Shanghai.
The use of "imperial capital" to mean Beijing has increased as Internet users have come to rely more and more on code words, homonyms, and creatively indirect references to avoid and circumvent censorship. "Imperial capital" is blocked on Weibo as of June 9, 2015.
Diyiweiwen (@第一微闻): In February I ate smog. In March I ate sand. In April I ate catkins. Today this damn meal has arrived!! Long live the imperial capital! (April 15, 2015)