According to the article by the Electronic Frontier Foundation (EFF) "Section 230 is Good, Actually"
Section 230 says that any site that hosts the content of other “speakers”—from writing, to videos, to pictures, to code that others write or upload—is not liable for that content, except for some important exceptions for violations of federal criminal law and intellectual property claims.
They go on to say,
Basically, Section 230 means that if you break the law online, you should be the only one held responsible, not the website, app, or forum where you said the unlawful thing.
Just to be clear, that isn't strictly correct, right? A quick wikipedia search shows that in Cubby, Inc. v. CompuServe Inc.
As a distributor, CompuServe could only be held liable for defamation if it knew, or had reason to know, of the defamatory nature of the content. As CompuServe had made no effort to review the large volume of content on its forums, it could not be held liable for the defamatory content.
In one source online, I even saw Section 230 described as
Congress enacted § 230 to remove the disincentives to self-regulation
So which is it? Does the removal Section 230 mean a site will be held liable for the content created by others? Or, does it mean that a site will only be held liable if they engage in optional moderation or acts of "publishing" (such as filtering and removal of offensive material). It seems like it's still the creator that is liable. And you can still have a free and open moderation-free internet in a post-Sec 230 world?
Update: On spam, the same case above Cubby, Inc. v. CompuServe Inc., 776 F. Supp. 135 (S.D.N.Y. 1991) states that,
CompuServe's ultimate right under the contract to remove text from its system for noncompliance with its standards merely constitutes control over the result of CCI's independent work. This level of control over the Journalism Forum is insufficient to rise to the level of an agency relationship.
With this text, I don't think it's sufficient to say that in a post-Section 230 world removal of content would be defamation per se, it seems it has satisfy some standard.