[leon_theremin]

It is not implemented on firmware, but as a silicon trojan. It doesn't use sound, but EMF.

It won't be exposed in full easily though as criminals with access to it currently work to prevent anyone from doing so.

[cookiengineer]

> It won't be exposed in full easily though as criminals with access to it currently work to prevent anyone from doing so.

Do you have evidence or links to articles supporting this?