I'm calling it now. The robots are gonna get us. First we give them artificial intelligence, then the deadly weapons and we're screwed. We'll build them to protect us, but trust me, they'll know they are stronger than us. If it's not the zombies, or the aliens it's the robots.
The aliens have already been probing us for centuries, they probably set up the robots. We use alien technology from world war two to build the robots, then the robots overtake human society, then the aliens come down to earth and rule along side the robots. Trust me the robots are in cahoots with the aliens. It'll start in Tokyo, and then next thing we know we're slaves to the robots. Oh the irony of it all.