Brilliant. Never even occurred to me. People often use headsets, wired or wireless, for the mic. Can just not enable audio unless one is plugged in. That's so easy to verify. Thanks for stating the obvious to my overly-complex mind. :)

:)

I've always found built-in/integrated cameras/mics to represent tremendous negative value.

1. I cannot unambiguously disable them.

2. I cannot upgrade / swap them readily for something better.

Aftermarket/detachable just seems such an obvious alternative.

And yeah, a simpler solution to a hard problem ;-)

Re battery eject: How can you be sure that the removable battery is the only one?

Fair point. Proofs are hard, but on a mass-market device, considerable secondary storage would be fairly evident in a teardown.

Microcurrent devices fed by a small cap or disguised secondary battery might function. But you'd have very limited capabilities.

You might well ask how sure you are that there's not a secondary microphone on the device, to which I can only suggest you cannot be too paranoid.