“Free Speech” means that you can say whatever you wish without fear of government reprisal. It doesn’t free you from all consequences. Twitter is well within their rights to lock you out of their service.
However, people are responsible for the things that they say. A great example of this is slander, libel, and defamation of character. If I make a statement as if it were a fact, yet I know to be false, and I made that statement with the intent of harming the person who is the subject of that statement, I am liable for that. Even if I made that statement with a careless disregard for any harm it would cause or a disregard for the truth of that statement, I am still liable.
For example, let’s say that I make the statement that someone is a pedophile. At the time I made the statement, I didn’t know or care whether or not it was true. If the community heard that statement and his business, career, or reputation is harmed, I am now open to being sued by him.
The reason why the press can publish stories about people is they make every effort to ensure its veracity. The truth is an absolute defense. This is why news organizations retract false statements publicly as soon as they realize it was false. Or at least why they used to.
The reason why sites like Facebook, Twitter, and other social media sites don’t get sued is that they have claimed to be a virtual town square where the site doesn’t have anything to do with the content, and are merely serving as a vehicle for free speech.
As soon as Social Media sites began controlling and eliminating speech that they disagreed with, they became editors who ensured that anything posted on their site was something with which they agreed. At this point, the statement is essentially their statement and not simply a posting of someone else’s statement. They are trying to avoid this by calling it “fact checking” and dodging their responsibilities. I think this is a fig leaf that should be eliminated, but we know how the courts are going to go.
I just don’t believe in our legal system or its courts. Heck, I no longer believe in our entire government. Sadly, it has been completely subverted.
In the case of Musk blocking people, he isn’t eliminating their ability to speak. He is simply refusing to listen to them, and that doesn’t violate anything.