Once robots have figured out how to replicate themselves, we're in trouble. So why did someone build a Lego machine that can then build stuff out of Legos, such as another Lego-building machine? Are you crazy?!
Engineer Will Gorman built this MakerLegoBot, which is able to take a virtual 3-D model and assemble it using Lego bricks. He hasn't tried to get it to replicate itself yet, but clearly that was in the back of his mind when he built the thing. It's a pretty neat trick, sure, but he won't be laughing when a pair of Lego hands are choking the life out of him.