At a recent meeting of the World Economic Forum, someone asked Stuart Russell, a professor of computer science at the University of California, Berkeley, when superintelligent artificial intelligence (AI) might arrive. He loosely estimated it to be within his children's lifetime, and then he emphasized the Chatham House rules of the meeting and that his conjecture was "strictly off the record." But, he writes in his new book Human Compatible: Artificial Intelligence and the Problem of Control, "Less than two hours later, an article appeared in the Daily Telegraph citing Professor Russell's remarks, complete with images of rampaging Terminator robots." Hyperbole by many media outlets has made it challenging for experts to talk seriously about the dangers of artificial superintelligence--a technology that would surpass the intellectual capabilities of humans. Nonetheless, many experts have written books on the subject.