In my own opinion, i feel fanaticism is completely bad. Lets look at the issue of Farouk Mutallab, his father is rich so what else would he become a terrorist for if not because he is a fanatic? Is it not in every religion that 'thou shalt not kill'? So if u kill people because they are 'Infidels' and u think you're doing God a 'favour' or you think it's right, then you are saying God is going against His Laws which is impossible.
Fanaticism will not make u think aright thereby making u believe anything the pastor or imam says whether it is right or wrong.
What do you think Nairalanders

One man's terrorist is another man's freedom fighter. Because Africans love to get anally penetrated by the white man doesn't mean everyone else does. 

I think it may mostly be politically motivated. Religion is just for PR.