If you want privacy, I guess you have to do it the old-fashioned personal meeting way. No recording devices. Deniability if that's necessary. Snapchat has the silly "this message will self-destruct", but someone can still point a camera at their phone to record it.

I don't see how doing it in person would change the logic. Aren't we saying that anything you do in public has no expectation of privacy? So some neighbor might be pointing a laser mic at your garden fence conversation from a window 80 meters away but hey, it's a public conversation!

That's how I feel when people say "oh there's no expectation of privacy cause you can just sign up with a fake name on a gift card."

That's even more insecure, as your neighbor might draw a gun then.