stenography (hiding meaning in something else)

Steganography? I’m assuming your autocorrect took over here: the manual form of steganography is exactly what I am talking about. Though come to think of it, I don’t know anyone who still uses, or can even read, the various forms of shorthand (stenography) that used to be so common; it could work as a hidden language these days. I bet some of the older ladies among us who were secretaries in the 50s and 60s could, though. When I was young I saw a book about learning it; it’s actually pretty brilliant and an elegant use of sound notation.

You nailed it with the lead pipe analogy, though, IMO. Truer words were never spoken. If the people watching never find you to be of any importance, if you are dismissed as too stupid or too sorry to deserve further attention, if you are seen as a waste of resources, you’ve conquered all the tech and cryptography and AI/ML and pattern analysis and digital surveillance an entire government can throw at you before they’ve even had a chance to start.