I don't think that any of us would disagree that violent-extremism is bad, at least in a highly illegal manner. I am of the opinion that non-violent extremists (like Phelps group) are also bad. Not in any legal manner(they obviously have free-speech like the rest of us) but in a manner that violates their own covenants. I was under the impression that 'Judgment is God's' or some such.
I don't mean to show disrespect, I'm merely unfamiliar with the scripture.