Citing your economic reason; but there are so many jobless, poor and destitute in countries around the world but they don’t harm or mass killing others except may be pick pocketing here and there. Moreover ISIS, Taliban killers are no poor or illiterate but richer and degree holder than others. Moreover many N2Is may be idiot and may be so. But the clear question is: where does ‘religious ego’ and mandate of religious killing come from???