I'm not so much worried about intelligences smarter than us. That might even end up being our salvation. I am worried about algorithms vastly dumber than us but more numerous, that interact with our tools and homes and vehicles, reacting to each other in sneaky and/or unpredictable ways. Driverless cars getting hijacked by advertisment software, excessive wifi signals causing drones to crash, facial recognition going horribly wrong, advertisements with eye-tracking capability that won't play unless you are looking at them ... stuff like that, only stranger and worse.