An interesting read I have to say. But what ISIS makes so extremely scary is neither their sadistic behavior, nor the PR for western media, but their PR for sunnits. If they show themselves as powerful force people, who are unhappy with their gov/lives, will join them and it's even enough to force 20.000 (!) soldiers with high-end equipment to flee. Another scary thing about them is the organization and decisiveness of their decisions. While they may are weak on the turkish borders, they are ceratinly not in other parts of Iraq