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I personally think that the answer is to standardize terms-of-service documents and to make them into real legal statements that both the website visitor and owner can make claims regarding, and that those statements be registered with a federal agency. The standardization should be so tight that filing it should be a matter of picking from drop down menus on a form, and the implications of each choice should be common knowledge and taught in school. The form should be able to be filled out anonymously (as "owner of [X] site.")
If you run a site without having filed one, though, you would lose legal protections as a publisher based on modding behavior. If somebody filing suit can point out any decisions that have been defined by law as constituting a specific degree of editorial control (examples: spam-control, abuse-control, subject-control, position-on-a-subject-control, arbitrary-control, etc.) then they will be responsible for libel/tort claims as a site for individual posts. A site that has filed a terms-of-service will get the benefit of the doubt, and the ability to push liability onto completely onto posters or maybe even individual mods.
Those requirements would either be too onerous to run the walled gardens of Web 2.0 at scale and small players will have a profitable business opening again, or the big dogs would be forced to really bureaucratize or democratize, and small players will have a profitable business opening by providing them modding services at the forum level.
And sure enough, we only banned one person ever. We banned him because he made a series of scary threats against the release manager, including "I know where you live", but these threats were made off-list, it was a campaign of personal harassment because no one wanted this idiot's patches. Suppose we had forgotten to include threats of violence off-list in our expected set of rules? And remember, we were talking about our mailing lists, which are forums according to section 230. So, would we lose our section 230 protections under your proposal?
In other words, you want to create more regulations that websites have to abide by. All that does is favor the big players even more than they're favored now.
> Those requirements would either be too onerous to run the walled gardens of Web 2.0 at scale
No, they would be too onerous for any websites other than the huge walled gardens to meet. All you're doing is setting up another form of regulatory capture.
> or the big dogs would be forced to really bureaucratize or democratize
Or they'll just buy the regulations that favor them, the same way they do now.
Bluntly, "would need to be litigated to find out" isn't an acceptable answer given that the people giving this answer are the same people proposing the legislation.
Courts don't decide what the law is, they interpret it. You have to have an idea of what you want the law to be, you can't kick that off to the courts. They're trying to interpret your intention and the letter of the law you propose, not the other way around.