Tech behemoths Google, Facebook, Microsoft, IBM and Amazon announced this week that they are teaming up to develop new standards for Artificial Intelligence (AI). Soon AI will change everything from warfare to our bodies. But we don't want to become slaves to the robots, so how do we stop the Terminators? A great deal of money going into AI is invested by defence companies. We need to put a complete ban on autonomous weapons, at least until we know for sure that they can apply the rules of war as well as humans.

Lots of work is going into the apparently simple, but in fact complex, field of turning things off. As soon as you give any machine a goal, even as innocent as making daisy chains, you give it the subsidiary goal of staying alive, because it cannot make daisy chains if it has been turned off. So any reasonably intelligent system will seek a method to disable the off button. It is the hardest technical challenge AI fans face. But there is no answer yet.