I'm not a lawyer, but my understanding of Section 230 is: Medium can't be sued if you libel your father-in-law by falsely saying he gets drunk on every family holiday and molests your cousins--but you could be sued.

And thanks so much for mentioning that some of the world's greatest authors at first had to publish anonymously (though some later dropped their cover or were exposed by scholars). It's very true that "posterity is the better" for their being able initially to hide their identities.

But I often have the sense that the privilege of writing under a pen name is being abused on Medium. It's hard to say for sure without knowing why people are doing it and what liberties they're taking with the truth. I wish Medium either wouldn't allow it or require members to disclose on their "About" pages that they're using pseudonyms.