Maybe it doesn't work. I've always wondered why, among so many long-ruling authoritarian regimes, China is almost the only one with such strict censorship. Yes there was the Arab Spring but look at Saudi Arabia, Russia, Belarus, Vietnam..., they don't ban Facebook yet the incumbents' rule do not face exceptionally greater challenge than China. Maybe all censorship does is to give the Communist Party is false sense of security. Maybe it's something else that's working and censorship is simply free-riding.