Even more troubling than Aliens, Russians or Chineses, would be if those devices were NAZI UFO, or worse, non-homo-sapiens-sapiens devices (say, remnants of som

Even more troubling than Aliens, Russians or Chineses, would be if those devices were NAZI UFO, or worse, non-homo-sapiens-sapiens devices (say, remnants of some ancient civilisation that lives hidden on (in) Earth.