To follow up, we've also tried going in the opposite direction from 230 more recently with SESTA/FOSTA.
From that Wikipedia page, some of the current effects (again, emphasis mine):
> Craigslist ceased offering its "Personals" section within all US domains in response to the bill's passing, stating "Any tool or service can be misused. We can’t take such risk without jeopardizing all our other services." Furry personals website Pounced.org voluntarily shut down, citing increased liability under the bill, and the difficulty of monitoring all the listings on the site for a small organization.
> The effectiveness of the bill has come into question as it has purportedly endangered sex workers and has been ineffective in catching and stopping sex traffickers. The sex worker community has claimed the law doesn't directly address issues that contribute to sex trafficking, but instead has drastically limited the tools available for law enforcement to seek surviving victims of sex trade. Similar consequences of the law's enactment have been reported internationally.
> A number of policy changes enacted by the popular social networks Facebook and Tumblr (the latter having been well known for having liberal policies regarding adult content) to restrict the posting of sexual content on their respective platforms have also been cited as examples of proactive censorship in the wake of the law, and a wider pattern of increased targeted censorship towards LGBT communities.
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Now, this kind of effect doesn't get as much mainstream attention because people are primed not to think of sex censorship as "real" censorship. But again, we have examples on the book of what happens to legitimate services (both large and small) when laws like this get passed. It's not fearmongering, it's history.
People have these assumptions that laws are going to be reasonably applied -- that's not a safe assumption to make if you pay attention to the history of these laws.
I'm largely unsympathetic to those arguments for the same reason that I'm unsympathetic to all of the lawmakers saying, "well this time we regulate encryption it will be different." We have a number of examples of how this can go wrong (and has gone wrong). If somebody wants to propose that it'll be different the next time we weaken 230 or add exceptions, then I think the onus is on them to provide some kind of compelling evidence as to why it's going to be different this time.
What makes you certain that the policies you propose won't have the same effect as FOSTA/SESTA?
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As to why these laws primarily affect platforms that are already trying to moderate and not free-for-all hellholes, that's in part because of existing case law around the difference between a publisher and a distributor.
From Wikipedia's entry on Compuserve's case (once again, emphasis mine):
> The court held that "CompuServe has no more editorial control over such a publication [as Rumorville] than does a public library, book store, or newsstand, and it would be no more feasible for CompuServe to examine every publication it carries for potentially defamatory statements than it would be for any other distributor to do so."
Bills like SESTA/FOSTA have managed to pass without a lot of opposition because, again, people are primed to think that sex censorship isn't real censorship. But where more mainstream content is concerned, you should understand that proposing punishments for distributors is a pretty big change to existing libel/speech laws. Big enough that I don't even feel comfortable speculating on what the legal challenges or possible effects would be. That's a radical departure from how we currently think about speech in the US, not just on the Internet but in physical/print spaces as well.