I think the bigger issue with the dominant social/publishing platforms is not a free speech, but their ability to ruin a business without ability of the business to appeal, go to court, sometimes even without a right to find the reason. They are increasingly becoming a marketplace and, as such, they have to be legally forced to keep it transparent and fair. Utility companies cannot turn your electricity off just because some clerk inside PG&E decided that you use this electricity in a way he personally does not like. YouTube, Facebook and Twitter do it many times a day.