> It would be an AI deciding that it needs to turn every bit of available matter on earth into computational power in order to cure cancer, or figure out a way to stop humans from fighting each other, or to maximize the profit of GOOG, and being so good at planning and deceiving us that by the time we figured out what it was doing, it was way, way too late.

That's how AIs worked in outdated science fictions. Current one don't have a bunch of mathematical rules that they follow to literally, but try to model what a human would write by statistical means with less logical capability.