China, Iran, Cuba
I could believe Russia, but the people who've been to Cuba I've met show its absolutely false. The Iranians and people who've traveled to Iran I've met suggest there are religious police that do suck, but it technically being punishable doesn't stop them from criticizing those cops to foreigners.
Have you and others tried to criticise the CCP, though
Yes, like all the time, you just have to ask about a specific policy someone has feelings on.
red herring
I'm trying to give a more general description of criticism and dissent within China.