AI will be 'dangerous' because humans will use it irresponsibly, and that's all of the risk.
- giving it too much trust, being lazy, improper guards and accidents - leveraging it for negative things (black hats, military targetting) - states and governments using it as instrument of control etc.
That's it.
Stop worrying about the ghost in the machine and start worrying about crappy and evil businesses and governing institutions.
Democracy, vigilance, laws, responsibility are what we need, in all things.