>people on mainstream platforms don't all know about or agree with those platform's moderation/censorship policies.
I will agree with you on this. I think the moderation policies should be clearly delineated or they don't really exist. A law is not much of a law if it's unequally applied.
You bring up an interesting point about "discovery" of view points you want to hear about, especially when you consider the foundation of the Internet as a platform: search engines. One problematic example I can think of off the top of my head is the "anti-vaxx" movement, which may be promoting a message that some people want to hear but at what cost to their children or the larger society who are subject to those parents' whims or beliefs? Very different than me discovering there are other people out there on the internet who are disturbed by the Garfield comic and want to joke about the existential horror of a cartoon cat and his owner.
I can't say that I have an easy answer for the issue of the harmful effects of a platform on the societies its users are members of. Or even determining what is harmful (or not).
If a society only allows 'harmless' speech, then it simply does not have freedom of speech, regardless of if it is enforced by law or private platforms. Much like in other areas (e.g. police powers), there is a balancing between rights/liberty, and security(1). At least when it comes to US law, this balancing was already done - the 1st Amendment embodies the opinion that allowing government censorship would be worse than allowing 'harmful'(2) speech.
That said, the situation has changed. Among other things, the ratio between the amount of speech, and the number of speakers or their resources is getting harder to determine, as is the origin of the speech(3), and the nature of the speaker. It could be an anonymous fellow citizen, a corporate shill, or an agent/bot of a hostile foreign government. The platforms themselves can also massively influence public opinion by suppressing some viewpoints, and promoting others (not by something as crude as censorship, but by changing the threshold of when a post goes viral). This effect is similar to that of media conglomeration, but harder to detect.
Personally, I lean heavily towards only banning "inauthentic behavior" (the mentioned shills and bots), as I believe Twitter refers to it, and allowing all other currently legal speech.
(1) Giving up some freedom may grant security from other people, but it reduces security against the state itself - the risk of abuse of authority increases, as does the harm a bad government can cause.
(2) Quotes not because I don't believe some speech is harmful, but because outside of a few narrow exceptions (probably coinciding with the exceptions to the 1st Amendment determined by the US Supreme Court), everyone has their own opinion on which speech is harmful and which isn't, and which should be allowed and which banned.
(3) Though the Supreme Court has on a few occasions ruled quite decisively in favor of anonymous speech.
I will agree with you on this. I think the moderation policies should be clearly delineated or they don't really exist. A law is not much of a law if it's unequally applied.
You bring up an interesting point about "discovery" of view points you want to hear about, especially when you consider the foundation of the Internet as a platform: search engines. One problematic example I can think of off the top of my head is the "anti-vaxx" movement, which may be promoting a message that some people want to hear but at what cost to their children or the larger society who are subject to those parents' whims or beliefs? Very different than me discovering there are other people out there on the internet who are disturbed by the Garfield comic and want to joke about the existential horror of a cartoon cat and his owner.
I can't say that I have an easy answer for the issue of the harmful effects of a platform on the societies its users are members of. Or even determining what is harmful (or not).