In the United States, whatever you may think of Julian Assange, even people who are not necessarily big fans of his are very concerned about the way in which the United States government and some companies have handled Wikileaks.
Thanks to the Internet in general and social media in particular, the Chinese people now have a mechanism to hold authorities accountable for wrongdoing - at least sometimes - without any actual political or legal reforms having taken place. Major political power struggles and scandals are no longer kept within elite circles.
There is a widening gap between the middle-aged-to-older generation, who still read newspapers and watch CCTV news, and the Internet generation.
Whether or not the U.S. government funds circumvention tools, or who exactly it funds and with what amount, it is clear that Internet users in China and elsewhere are seeking out and creating their own ad hoc solutions to access the uncensored global Internet.
Digital activism did not spring immaculately out of Twitter and Facebook. It's been going on ever since blogs existed.
The trend in China is toward tighter and tighter control. They are basically improving their censorship mechanisms.