The reason that it is the case that "things are this crazy in China" is that there is a difference between the existence of people who would probably enjoy implementing crazy policies and the actual implementation of crazy policies.
As we saw in the FLQ Crisis and again during the G20 summit, Canadians can lock thousands of people up without due process of law. As we saw in Kansas, certain Americans can ban the teaching of established science in the classroom.
But our system at least makes these things aberrations and provides dissenters a way to rectify the problems in the courts.'
edit: I think what I'm trying to say is "Our system provides us with an undo, but it's only good when we remain vigilant against craziness. If we become complacent and assume that we as people are somehow too intelligent or too morally centered to do crazy things, wham, we do crazy things too."
What a lot of people don't get when they try to tu quoque US/Canada/etc on particular events is that their protection of essential liberties is defense in depth.
If a book was banned:
- due process means that this incident can be taken to court
- freedom of press means the mass media can inform others of what has happened
- freedom of speech means you can raise awareness about the banning and denounce the agencies responsible
- with freedom of assembly, those who want the ban overturned can take to the streets and protest
These freedoms are mutually supportive -- abuse of any aspect would be mitigated by the presence of the rest.
And in the most extreme, the freedom to keep and bear arms means that we've got the ability to boot out an unjust government.