> They exist. They are real. They aren't ours. They aren't an adversary's, because a) the military would never admit it if that were possible and b) if it were the case the adversary would have already taken over the world.

can't speak to a), but as for b), it is possible that what they are and what they appear to be are very different things. Imagine, say, a drone swarm with a very flat profile that could turn their surfaces towards a target and tighten up to present a radar cross section and become highly visible, but could flip to an edge-on position and disperse to disappear to both eyes and instruments. Two such swarms could easily mimic an instantaneous movement over a large distance, among other effects.

In other words, they might be moderately more advanced technology masquerading as ludicrously more advanced technology, presenting the appearance of a threat far greater than their inventors can actually produce.