Free speech does not apply in any of these cases. These are all privately owned platforms. The first Amendment protects the populace from the government policing speech.
How many times is this tr[oi]pe going to be blindly repeated before its promoters bother to look up the definition of free speech and find it's a more general concept than simply the first amendment to the US Constitution?
I suppose this misbelief is itself a demonstration that truth and justice do not necessarily prevail in open argument. Still, we are better off with many terrible ideas persisting than to further allow those in power to arbitrate truth.
