[mardifoufs]

As it says in the article you linked, this type of situation js practically the opposite of what was described in Popper's book:

"Nonetheless, alternative interpretations are often misattributed to Popper in defense of extra-judicial (including violent) suppression of intolerance such as hate speech, outside of democratic institutions, an idea which Popper himself never espoused. The chapter in question explicitly defines the context to that of political institutions and the democratic process, and rejects the notion of "the will of the people" having valid meaning outside of those institutions. Thus, in context, Popper's acquiescence to suppression when all else has failed applies only to the state in a liberal democracy with a constitutional rule of law that must be just in its foundations, but will necessarily be imperfect."

I'm not sure how Facebook posts are literal physical violence. Also, it's so weird to keep seeing this supposed paradox cited (incorrectly) ad nauseum to justify basically any infringement on free speech when it was barely a concept he wrote about in passing, with very little thought put into it by Popper himself. Even if it was used correctly, It's just a very small thought exercise written by an author almost a century ago, it's not a natural law lol.