Soon cars, buildings, cities, and people will have sensors and software that track resources, respond to crime, or take constant vital signs. In that environment, machine learning will become increasingly important—not insane robots but systems much smarter than today’s Google searches. Once we’ve connected everything to everything else, safety and privacy will be big challenges. It’s impossible to stop abuse, but we have to be able to detect it. We need to develop better security and authentication technology, as well as better international agreements to prosecute cross-country cybercrimes.