That only helps if the spy equipment needs more than power from the USB port. It doesn't need a data connection if it's picking up RF noise from the laptop and

That only helps if the spy equipment needs more than power from the USB port. It doesn't need a data connection if it's picking up RF noise from the laptop and audio from people to transmit to nearby agents. It was done in the '80s with much less advanced technology: http://www.cryptomuseum.com/covert/bugs/selectric/ http://www.cryptomuseum.com/covert/bugs/selectric/