Recently a former student of The College of Saint Rose in Albany, New York destroyed tens of thousands of dollars worth of campus computers by simply plugging in a USB device. This device creates electrical surges to shut down computers or destroys them completely.
The USB device circuitry does this by an inverting DC/DC converter runs and charges capacitors to -110V. When the voltage is reached, the DC/DC is switched off. At the same time, the filed transistor opens. It is used to apply the -110V to signal lines of the USB interface. When the voltage on capacitors increases to -7V, the transistor closes and the DC/DC starts. The loop runs till everything possible is broken down. What’s scary is these “USB Killer” devices can be easily purchased online and has no defense.
As for the Student, he has pleaded guilty and now faces up to 10 years in prison and a fine of $250,000.