I would look into antitrust laws in regards to Facebook, Twitter, and Google working together to control what is allowed on social media. Gas companies cannot collude to set the price of gasoline as that is their product, hence social media companies cannot collude to suppress certain types of speech as speech is their product.
... speech is their product...
Their product is personal user data. What individual members say has no market value. Facebook censors certain users because they can as a monopoly, and because FB management are fascists.