Back in 1999 my daughter was working inHong Kong, so my brother and I went out to visit her. At one stage we were standing in a car park admiring the bridge across to the new airport when a couple of coaches arrived full of Chinese tourists. With much giggling a number of them came across to take our photographs. Why? Because we both have full beards - virtually non-existent in China.Yup, Chinese society is the ultimate expression of Political Correctness, where not only is it not "not done" to say certain things, it is illegal, with severe punishment for transgression. Death can be the result of saying the wrong words or doing the wrong things (see Tiananman Square 15 Apr 1989 – 4 Jun 1989), where a man has the bravery to stand in front of a row of tanks, and is later probably executed for doing so.
Don't anyone be fooled by "Chinese tourism". The Chinese tourists you see are the ones who are allowed out - those who are deemed "politically safe" - sufficiently indoctrinated to risk exposure to Western culture.
A more relevant memory is from a long vac visit round the Soviet Union in 1961. Our Intourist guide arranged a visit to Moscow University, where we were shown round by a couple of students. Earlier that morning we had seen an Embassy flyer announcing that the Soviet Union had just broken a test ban treaty. We mentioned this to our guides and their reply was "They will tell us when they want us to know".