> None of us know for sure but I think the immediate threat of the drones is negligible. If US bases are leaking signals that can be intercepted by drones overhead then these same signals could be just as easily intercepted by cars driving past the bases or nearby homes. And as far as the visible spectrum is concerned all the major players have satellites overhead anyway.

You can also do radio frequency signals intercepts from space, too. You need a big antenna on your satellite, but it's essentially a solved problem. Spaceborne SIGINT goes back to at least the early 70s.