Today I learned that you can actually abuse the system bus on some macbooks to actually send audio over AM radio[0]. Even scarier, you can do it from the browser[1]. And now this library[2] will let you open a TCP connection over the radio to download off that data machine. This is shaping up to be a pretty cool attack PoC!
Code running in your browser gaining a TCP connection seems like the least scary use case of this possible- presumably it already has a TCP connection in the first place.
That reminds me of the programs you could run on a TI-83 calculator that used a similar approach for playing sound on headphones or a nearby AM radio: http://www.pacmeb.com/calc/features.php
[0]: https://github.com/fulldecent/system-bus-radio
[1]: https://fulldecent.github.io/system-bus-radio
[2]: https://github.com/quiet/quiet-js