Daphne Keller:

Many would say there is a moral imperative for platforms to take down legal-but-offensive or harmful speech – including seriously disturbing material like Holocaust denial tracts and suicide how-to videos. In any case there is a clear commercial reason for platforms to weed out content of this sort, since it alienates both users and advertisers. That means we are unlikely to get away from some form of the current situation: platforms enforcing discretionary rules that ban legal speech, and users disagreeing vehemently with the platforms’ choices.