Cue the resurgence of lip reading-based espionage. Imagining having to scan the room for people watching subvocalizers. Will subvocalizers start holding up a clipboard over their face a la NFL coaches?

That's already been a problem ever since people figured out you can recover voice from watching the subpixel vibration of objects within a room. (Video: https://www.youtube.com/watch?v=eUzB0L0mSCI)

There is a reason secure activity happens within secured rooms built to a specific standard https://en.wikipedia.org/wiki/Sensitive_compartmented_inform...

Thought of the same! Cue George Orwell facepalming in his grave.