If software that actually exists is really already sending "telemetry" that can reliably identify your activities in the real world the concern isn't that theoretical anymore.

You can tell that an application accesses the microphone these days.

It's not that simple. An application could have access to the microphone, but an OS could be providing the mute functionality, thereby not passing any data to the app even if it keeps access to it (there are hardware/software issues with releasing and reaccessing it with extremely low latency like one expects of a mute/unmute button).

The problem, as reported in the article, is that apps are not making use of the OS mute, but are instead still reading from the microphone, and some are even passing the readout to their servers.

On Macos, there is an indicator dot in the status bar, on all chat apps, the mic dot is always active while the camera dot does turn off when the camera is disabled. The most likely situation is that turning the mic and camera on at the OS level has delay which is acceptable for turning on video but not for audio where you want to be able to respond to something quickly.

> But that's true for literally all applications running on your computer. Evil software running on your machine can do all sorts of bad things.

This is why I personally insist on using the web version of streaming software over an installed binary.