They're rare that we know of. If the various intelligence/security institutions know how to find/train them, surely they wouldn't tell everyone as it then dest

They're rare that we know of. If the various intelligence/security institutions know how to find/train them, surely they wouldn't tell everyone as it then destroys their tactical advantage. I'm not suggesting that I know they're common by any stretch of the imagination. But to say that you know they aren't is intellectually dishonest.