But neither of them, in and of themselves, is abuse. Yes, they might be promulgated in a way that becomes abusive (sending racist opinions repeatedly as you mention, or sending your followers to harass a PR department because they didn't include a trigger warning), but censoring either opinion, outside of abuse, falls into the same trap of playing not the responsible platform, but engaging in censorship. If you consistently censor one and not the other, then you are a biased censor.