Another German film from the same period as Kuhle Wampe with an anti-authoritarian slant that's well worth seeing is Madchen in Uniform (1931, directed by Leontine Sagan). A touching tale set in a girls' boarding school, with one of the girls falling for a tender, beautiful teacher. Needless to say, it didn't meet with the Nazis' approval. I'll second Mr West's recommendation.