@avlcharlie In that example, yes, because *you* said it, *you* are responsible.

But with social media, each user publishes their own speech. The company is hosting and amplifying the speech, not saying it themselves.

So, in your example, this is less like writing down what they say and repeating it, and more like just handing them the megaphone, which is a crucial difference. If a social media company actually did repeat your words under their own account, I don't think 230 would protect them, because then the speech would no longer be 3rd party.