The only remedy for this is for real citizens to go full vigilante on their arse. Sovereign Citizen plates on are car are a request to have your tyres slashed.
Honestly, I have more respect for a criminal who doesn’t have plates, or has stolen plates because at least they admit that they are breaking the rules.
SovCit idiots are just fucking idiots who think that the laws do not legally apply to them.
It is absolutely atrocious to use and constantly tries to ram Algorithmic crap down your through. The thing is, most normies are there and for every person who is Internet savvy enough to see the benefit of Mastodon and Lemmy (and Pixelfed, etc) there are a dozen normies who don’t and can’t be bothered finding out.
I would not say that Facebook is popular, but I will say that it is common. It is literally the Lowest Common Denominator for port of social interaction on the Internet.