While a controlling state wishes to limit expression, citizens creatively employ every possible communicative modality—music, video, images, Arabic numerals, puns, Chinese characters, Roman letters, foreign words, writing, speech, sound, vision—and choose among varieties of speech and writing at their own discretion. The resources they employ reveal limits to the officially enforced boundaries—linguistic and conceptual—of China.
http://blogs.nottingham.ac.uk/chinapolicyinstitute/2015/06/16/linguistic-challenges-to-chinas-centralizing-control/