Unless you’re just upgrading from windows 3.1, you’ve seen the cheap SDR (software defined radio) rtl-sdr project. SDR’s aren’t new but someone figured out how to turn a cheap sub-20$ dongle into a decent SDR bringing the entry price low enough for everyone to experiment with them.
Melissa Elliott has put together a presentation titled “exploring the world of unintentional radio emissions” that was presented at DEF CON. After talking about the concept itself, she shows you how almost everything that runs on electricity emits some sort of electronic signature. That signature can be profiled and sometimes data can be decoded from it.
No it’s not time to break out the tin foil hats or anything but if you really are paranoid, Melissa gives some tips how to shield this information in the form of Faraday cages. You don’t have to be an old ham radio buff or even a budding electronics engineer to appreciate how cool SDR’s are.