I think that most of us have seen that meme about Karl Popper's Paradox of Tolerance, which absolutely gets what Popper said wrong. When the meme gets it wrong, it stands to reason that most people sharing it are getting it wrong.
The thing is, the meme ends with Popper making the declaration that tolerant people must be intolerant of intolerance.
I'm starting to think that much of the misreading of Popper comes from a lot of people not knowing what a paradox is to begin with. On top of that, they try to extract oughts from what Popper viewed as an is.
If Popper meant this passage to be taken in the normative sense or to be seen a a declaration of what is right, he wouldn't have used the word "paradox." If he were arguing for the level of intolerance that most of the sharers of this meme support, he should have used like "limits" or "flaws" in regard to tolerance.
Paradoxes are statements or propositions that seem absurd or contradictory that may be true. Paradoxes aren't moral prescriptions.
The anomaly in the TNG episode All Good Things existed as a paradox that was created in the future and threatened the universe by growing as it moved further into the past. The simple fact that it was a paradox doesn't change any moral assessment. The character in Heinlein's " '—All You Zombies—' " exists as a paradoxical being. There's no ought to be extracted from the characters existence as a paradox.
Likewise, Popper was pointing out that tolerance, as a concept, exists as a paradox. He was not saying that tolerant people must not tolerate intolerant people in this context, at least not in the normative sense. What he was saying is that the paradox is an unavoidable component to the concept.
Popper went on to make his share of normative statements about tolerance and its function in liberal society. It's safe to say that his views were classically liberal and he was a staunch advocate for free speech, including for intolerant people.
The thing is, understanding that tolerance is conceptually paradoxical does allow people to operate within that understanding and draw their own conclusions. We can debate within that framework. Where you show that you don't know what you're talking about is where you point to Popper, and this specific passage by him, and say, "See? He agrees with me that we have to not tolerate intolerance."
I think that's partly born out of our desires to explain everything. Part of the fun of paradoxes are that they often are just what they are.