Privacy brings security under totalitarian regimes or in countries that shift in that direction. They might say if you have nothing to hide, you have nothing to fear, but there are unjust conditions under which you have to hide things, like that you belong to minority that is targeted by the authorities. Like the nazis did in the third reich, where privacy was reduced during their takeover. Or that you belong to a party that is suddenly framed as evil and enemies of the nation. Or if you have connections to “traitors” or other “scum”.

There were no actual efforts to establish communism in eastern europe. Only autocratic regimes backed by soviet russia.