I recently saw a large London airport come to a grinding halt due to an invisible UFO. Of course, the government will deny it ever happened i'm sure, put it down to a weather drone maybe. Probably find some old wreckage from a previous drone and claim it was that, and have some poor buggers pose in the press a few days later looking upset, puzzled and confused. Nah....wouldn't happen, such an imagination I have. Maybe a few years from now we could have 'Project (DJI) Phantom' and an assembled group of the 'Mavic 12' to covertly investigate such mysterious an unseen objects.