“These concerns imply that social media is a lawless mayhem when it comes to hate speech. But this characterization is wrong. Most platforms have strict rules prohibiting hate speech, which have expanded significantly over the past several years. Many of these policies go far beyond both what’s required and permissible under international human rights law (IHRL).”
See also the Future Free Speech report – Scope Creep: An Assessment of 8 Social Media Platforms’ Hate Speech Policies