In Chapter 24, why are each of Jung Chang's parents sent to detention camps?

Jung's parents are sent to detention camps mainly because her father personally challenged Mao, saying of the Cultural Revolution, "There is nothing cultural about this. This is only brutality!", and begging Mao, "as one Communist to another", to stop the Cultural Revolution. There are also multiple other (false) charges against her parents of infidelity, cowardliness, and consortion with the Koumingtang.