I think that it is entirely possible that many of the more millitant 'crazies' listed above may in fact have a sociopathic difficulty, i don't think that having 'irrational' beliefs constitutes mental disorder. i think it would instead qualify as wittgensteinian 'mistakenness'.
any outside mental disorder may facilitate millitant reactions, but belief systems are not symptomatic of this i think. i have decided recently that i no longer believe that the dirty towelheads had anything to do with september 11 and it was instead perpetrated by the government a la reichstag. does this make me crazy? no. but it may be exemplary of the way my brain interprets information. this may be environmental or inherent.