[HocusLocus]

MICS without physical disable switches that actually short input to ground through a resistor (open circuits can leak) are always a problem. It's more of a "Darwin in action" issue because during a critical period that people could have demanded this real and effective solution (the 1990s and early 2000s) they didn't seem to care.

Then laptops took off as primary computers and people were no longer installing their own peripherals any more, and demanded no external circuit-interrupting switches not even for cameras.

Back in the 1990s I was telling people, your plain speakers are not safe either (from being used as listening devices) as long as they do not have their own amps and are driven directly by a chip in the computer. How much do you know about that chipset and who makes it? One of the major early chipset players was Realtek.

Then some Ben Guriron researchers burst onto the scene in 2016 ( https://www.usenix.org/system/files/conference/woot17/woot17... ) with a real proof of concept where they used a jack assignment matrix in (you guessed it, a Realtek chip) to turn an idle pair of headphones into a listening device.

I'd be interested to hear anyone who heard the other shoe drop. I don't doubt that an internal assignment matrix facility exists in many modern chipsets. It would take a concerted and deliberate effort to mitigate this kind of vulnerability. Has anything like this been done?