well, we did just see a 3D printed weapon used, but the stories about the perp's looks shouted over the other details. I'm sure the gun lobby was pleased with that. so to the idea of school shootings, drone swarms would probably be too much for that, but a kid printing up their own guns to use is definitely something I could see happening. drone swarms would to me still be limited to a more well funded group to achieve instead of a lone wolf scenario.