[melpomene]

> Don't they understand that it is not technically possible? People will just start using VPN.

Maybe it is not possible to completly stop it, but they could just implement severe punishments for trying to connect to services like TOR, I2P and VPNs. The traffic is definitely detectable, (here is a project that tries to make it harder to detect TOR traffic http://www.owlfolio.org/media/2010/05/stegotorus-talk/). Even if they can't catch them all they can catch and punish enough people to make it to dangerous to use a VPN/TOR/I2P to not make it worth the risk to access the uncensored internet.