content: I think you missed the point of the article. The output jack is somehow able to be re-purposed as an input jack. This seems like they stumbled upon built-in spook tech. It's very clever, and I think some spy agencies aren't happy this has been found out.  Their malware uses a little-known feature of RealTek audio codec chips to silently “retask” the computer’s output channel as an input channel, allowing the malware to record audio even when the headphones remain connected into an output-only jack and don’t even have a microphone channel on their plug.