Section 230 of the Communications Decency Act grants common carrier liability protections to websites that publish user generated content. You’re right that the

Section 230 of the Communications Decency Act grants common carrier liability protections to websites that publish user generated content. You’re right that they’re not common carriers (because they are in fact allowed to discriminate in any way they choose), but I was exclusively referring to the liability protections they are afforded by the law.