Forbidden Feeds: Government Controls on Social Media in China is a report by PEN America that provides some insights into the development of censorship and surveillance of Social Media in China and its impacts. PEN America is a group that works to champion freedom of speech for writers. The report they have put together provides an overview of Social Media and its censorship in China and its implications for writers. The report features some of the work done by the Citizen Lab based in Toronto on the more subtle and insidious implementation of censorship.
The report provides a good reader for those looking to get an understanding of the mechanics of large scale censorship and surveillance.