The US still has a crime of, and recent prosecutions for sedition! A crime abolished as a relic in some other places. Pot, kettle, black? :)
The US constitution is very clear in its wording on free speech: "Congress shall make no law [...] abridging the freedom of speech". It is unfortunate that our judiciary has chosen to turn a blind eye to this and many other affronts to the rights of American citizens.
If an immigrant overstaying their Visa publicly declares their status to an immigration agent, they can get deported. Did this violate their right to free speech? If a person's public speech is so vile that everyone agrees to not listen to them, does this violate their right?
What we are actually talking about in this case, is morally (because of course, we have no rights to free speech in Australia) what are the acceptable restrictions that should be placed on people or businesses, to restrict others rights to speech?
And is the restricting of the right to silence others (say on your platform), in itself not a kind of restriction of right to your own speech?
This is much, much more difficult to answer consistently.
I think that your first example is also not a violation, as it is not an opinion. I think that this example reveals a more potent problem: what do we classify as opinion? As to that, I have no answer; I am no philosopher.
As for the morality of restricting others' right to free speech, it is definitely a difficult problem. Morally I think that you have no right to silence others because you disagree with their opinion. There is some nuance here; if HN deletes a post advertising viagra I don't think this is silencing someone. Similarly, deleting a post containing the results of a football game to a programming forum is also not silencing someone. There is an aspect of relevancy at play. If you choose to operate a general purpose forum, morally you are pretty limited in what it is acceptable to silence.
These are just my off-the-cuff thoughts. I might be missing something obvious here; it seems like a confounding problem.
>If you choose to operate a general purpose forum, morally you are pretty limited in what it is acceptable to silence.
I sort of agree, but isn't this almost tantamount to forcing people to listen? Philosophically, rather than actually of course, there is no clear line.
And why should speech be limited to opinion? It is free isn't it? And where has there ever been any verifiable line between opinion and fact? I would argue fact is a subset of opinion, and that all speech is actually opinion.
That is why I stressed the importance of only limiting the effects of speech, rather than the content. It maintains the rights, but also the responsibilities of the speaker.
Other nations have been more free amending their constitutions. Nations without written constitutions often consider that a feature not a bug. These can bend things out of shape differently. :)
It is perfectly possible to speak against the government, any government, without being racist, or inciting hate. It is not possible to speak against a government if you can't ridicule or caricature the head of state, or party a. Thus you can have free speech without also giving unlimited licence to be an offensive, racist jerk without consequence.