The` term “chareidi extremist” I believe is an oxymoron, part of being chareidi is going the “middle path”, meaning following the Torah but not making a Chillul Hashem, HaRav Ahron Teitelbaum (one of the Satmar Rebbes) once said not to go to the Anti-Gius rallies because they are a Chillul Hashem, regardless of the fact that the rallies are for a good cause, (according to Satmar at least, I’m trying not to offend any pro-gius people, inasmuch as I disagree with them).