Steamlyannaya Hamonika (1968) depicts the isolation and brutalization of humans in modern bourgeois society. Although being broadly in line with other art-as-propaganda of the era, censors felt it could easily be read as a criticism of the party, leaving this subversive short as the only animated film to be banned in the Soviet Union.

source: https://youtu.be/yVmw3ZhdzEs (https://piped.video/watch?v=yVmw3ZhdzEs)