Lemmy

Yup - it is, partially, Popper's paradox of tolerance.

However there's a second risk that I mentioned there, that Popper doesn't talk about: that the mechanisms and procedures used to get rid of the intolerant might be abused and misused, to hunt the others.

I call this "witch hunting", after the mediaeval practice - because the ones being thrown into the fire were rarely actual witches, they were mostly common people. You see this all the time in social media; specially in environments that value "trust" (i.e. gullibleness) and orthodoxy over rationality. Such as Twitter (cue to "the main character of the day"), Reddit (pitchfork emporium), and even here in Lemmy.

[from your other comment] There is another solution. Make it so witches cannot cause harm, everyone gives a little bit to make everything work for everyone.

It is trickier than it looks like. We might simplify them as "witches", but we're dealing with multiple groups. Some partially overlap (e.g. incels/misogynists vs. homophobic people), but some have almost nothing to do with each other, besides "they cause someone else harm". So it's actually a lot of work to prevent them from causing harm, to the point that it's inviable.