I think some people just gravitate towards causes that have active violence in them and some people are more prone to committing violence out of fear. Talking about the folk who don't need to have been bombed to fuck and seen their family murdered before they get stabby - talking about the ones in an otherwise safe, sane environment that end up extremists.
Atheism isn't believing in nothing - you believe there is no deity. Militant atheism seems to be a sliding scale of believing that religion should be eradicated. That is a belief which could lead to violence once it gets in the wrong people's heads.
-- boobs do nothing for me, I want moustaches and chest hair.