Model trains aren't just a toy. When hobbyists get serious about them, you can end up with the amazing 14,000 square foot Miniatur Wunderland in Germany. Click here to watch the mind-blowing video.
Even that amazing train set, however, doesn't take things to the level of "Project Honey Train." And no, this isn't a miniature railroad for bees.
Project Honey Train is a 1:87 scale model train surrounded by a made-up German city; the street names are actually based on Monopoly names. But while the train is a model, and the city is made up, the computers and software controlling the train are very real.
In fact, to any hackers poking around the Internet, it looks like they've stumbled across a system that controls an actual full-size train. Why does that matter?