The $56 USB Killer is an electrified USB stick that will fry a laptop
by Cory Doctorow from on (#1TWA1)
https://www.youtube.com/watch?v=3hbuhFwFsDU
For a49.95, you can own a "USB Killer" that "instantly and permanently disables unprotected hardware" with a 200V DC shock. The a13.95 USB KILLER TESTER is a shield that blocks the killer from actually delivering its voltage to your machine (buy the tester, get the killer for half price). (via Schneier)