Graffiti Drones
I'm a big fan of street art. I'm also a technologist. I never put these two together, but some intrepid person realized that drones can carry cans of spray paint and reach surfaces that a single person might not be able to.
They don't do a whole lot in this video, other than deface a large billboard ad. It's barely discernible, even in daylight. But I'd guess there's a street artist out there right now who's programming a drone swarm, each sporting a different color, to quickly and stealthily vandalize the side of a building.
The future never seems dull.