Plus, from what I see, the problem reduces to a form of computer security against a clever, malicious threat. You contain it, control what it gets to learn, and only let it interact with the world through a simplified language or interface that's easy to analyse or monitor for safety. Eliminate the advantages of its superintelligence outside the intended domain of application.
That's not easy by any means, amounting to high assurance security against high-end adversary. Yet, it's a vastly easier problem than beating a superintelligence in an open-ended way. Eliminate the open-ended part, apply security engineering knowledge, and win with acceptable effort. I think people are just making this concept way more difficult than it needs to be.
Biggest risk is some morons in stock trading plug greedy ones into trading floor with no understanding of long-term disruption potential of clever trades it tries. We've already seen what damage the simple algorithms can do. People are already plugging in NLP learning systems. They'll do it with deep learning, self-aware AI, whatever. Just wait.