"How not to build the Terminator" - two disturbing days at the 'world cup' for robots

What really happens at the US Defence Agency’s annual robotics showdown, and what are Uber, Amazon and Elon Musk doing in the crowd?
• Humanoid robots – in picturesIt’s surprisingly transfixing watching robots – great, lumbering, 7ft-tall humanoids – trying to walk and use power tools and drive a car. But it’s not the only spectator sport on hand at the Darpa Robotic Challenge. There’s also spot-the-billionaire. The first one I clock is Larry Page, co-founder of Google, who walks