Unless people decide to pressure the third party into de-platforming someone, which is their freedom of expression. I don't understand why the free speech absolutists on HN are incapable of understanding that private citizens pressuring a company to take action against a hate site is equally as much free speech as the hate site itself. By your own standards, nothing objectionable is occurring here. They just want to be contrarian.

There's pressure, but at some point, it can cross the line into extortion (which is not protected).

Let me know when it crosses that line then.