From a Bloomberg view column about Cuba: "At least since 1956, the Soviet system was being criticized in the USSR itself."
The suggestion seems to be that before 1956, Russians were in such a state of bliss under Stalin that no one wanted to criticize the totalitarian rule they were under, or that those who wanted to criticize it did not have the courage to actually do it. Or that after 1956, the Soviet Union was somehow receptive to criticism from its citizens. None of those suggestions is accurate.