Returning to BEagle's original post on proposed EASA Drone Legislation. The draft proposals mention 'Drone Swarms' or 'Formation Drones' ... I suspect when the technology becomes more robust (not that far away) this type of operation is going to need some serious thinking about.
A video worth watching ...
https://m.youtube.com/watch?v=YQIMGV5vtd4
Coff.