I think you are thinking of the american First Amendment, but just because corporate censorship doesn't fall foul of that, it doesn't mean it isn't a thing. Yeah there is corporate censorship. Not only on the internet, but when even when it comes to traditional media, newspapers, publishing, studios, writers and artists often need to deal with censorship that companies they work for or with imposes upon them.

Considering that private companies control the vast majority internet communications, there isn't even a public social media in the way that there are public physical spaces, and social media companies aren't neutral parties in the way that mail and phone services are, as common carriers.

But I get the sentiment here, that platform owners have the right to control what happens in it in the same way a hosts can set rules of conduct and have the right to kick you out for not following them. But in practice it's pretty messy. Some rules are reasonable for polite coexistence and others are just overbearing whims, or downright prejudice.

LGBTQ people regularly have to deal with their existences being deemed obscene. The most modest images and basic information about them is treated as unnacceptable. They get their posts hid, removed or they get downright banned. You could argue that the owners have the right to do this, but is it a good thing that this happens? Whatever you may think, it is censorship regardless.

At best of times it's difficult to find a balance of how platforms ought to be handled, but unfortunately they aren't always handled with good faith considerations for interests of the people in it. I believe that a lot of people are here because they had to face that.

Aye corporations can do no wrong, they've never tried to censor unions or the working class.

This is a semantic argument made to ignore the issue. The reality is that social media platforms effectively have become the "town square" where ideas are shared. Stifling legal speech in that environment is very effective censorship of ideas.

You can argue that corporations have that right because they own the network. I disagree. Curation of what can be said on their platform turns them into a publisher, not a communications provider. Any lawyer active in that space could tell you how insanely detrimental it would be for that distinction to be made, at least in the U.S.

Imagine your phone company deciding you can't say certain words to other people using their service without facing dropped calls, suspensions of service, or being banned. All because your legal speech goes against the morality of the majority.

That's essentially what social media does at the moment. They are legally defined as, and receive the benefits of, a communications service. But they are acting like a publisher, deciding what is and is not allowed to be said. It's a serious problem.