In Fantastic Beasts, the Second Salemers go around preaching warnings against witches and witchcraft. It seems to me equally plausible that either a) somehow, Mary Lou learned about MACUSA and the magical community and is protesting against them, or b) that the Second Salemers are simply paranoid religious fanatics preaching against witchcraft, with no knowledge of the actual wizarding community.

Is there any canonical evidence either way?