In front of a suburban house on the outskirts of the northern Germany city of Hamburg, a single word -- "LAION" -- is scrawled in pencil across a mailbox. It's the only indication that the home belongs to the person behind a massive data gathering effort central to the artificial intelligence boom that has seized the world's attention. That person is high schoolteacher Christoph Schuhmann, and LAION, short for "Large-scale AI Open Network," is his passion project. When Schuhmann isn't teaching physics and computer science to German teens, he works with a small team of volunteers building the world's biggest free AI training data set, which has already been used in text-to-image generators such as Google's Imagen and Stable Diffusion. Databases like LAION are central to AI text-to-image generators, which rely on them for the enormous amounts of visual material used to deconstruct and create new images.