Part of me, thinks that their systems were attacked, but being into security, I've though a lot about how to attack a large computer system like this. Since server failiures are so common, the system should be able to handle N failiures before anything bad happens. If this was an attack, I guess the attacker must have found a flaw that allowed them to instantly compromise any server. But it actually seems more likely that this was caused, merely, by incompetence.<p>If the attack was possible, than it was just as likely, if not more, that Delta managed to merely shoot itself in the foot.