Google uses this kind of Authentication for Chromecast when a User isn't connected to the same Network as the Chromecast is. This way you can still send Videos. It's called Guest Mode or something and is Opt-in
Zoom does some kind of ultrasonic sound in Zoom Room AV systems to automagically pair your computer to the room. Unfortunately I can hear it (though none of my coworkers can) as a periodic high-pitched chirping.
