My understanding, entirely possible that it is incorrect, is that the "not causing interference" is to "authorized services", i.e. specifically licensed frequen

My understanding, entirely possible that it is incorrect, is that the "not causing interference" is to "authorized services", i.e. specifically licensed frequencies and users/devices, not other users of those "free-for-all" spectrums. But I may well be wrong, in which case I would agree with you.