[ThePhysicist]

I would say that the Chromebook's USB ports are probably to blame as well. Shorting the +Vpp pin to GND should only result in sinking the maximum current but not in the port being damaged. Likewise, I'd expect the signal port to be protected against shorting it to GND or connecting it to a (moderately) high input voltage. The USB standard does probably not require these kind of protections, but they are nevertheless good, defensive design for any port that gets connected to a large number of unknown and potentially dangerous / badly designed devices.

Btw I already destroyed some parallel, serial and USB ports when connecting them to devices I built that malfunctioned or were ill designed (during prototyping), so as a measure of safety I now often use optocouplers to galvanically isolate my circuit from the port, which can help to prevent most kinds of damage.

[cesarb]

This was not shorting +Vpp to GND; this was putting -Vpp in the +Vpp pin. All pins are referenced to GND, which is 0V by definition, so if you put +5V in it, it's the same as subtracting 5V from the voltage in all the other pins. And since they put the 0V in +Vpp, it became -5V. Most devices aren't prepared for negative voltages.

[ThePhysicist]

Point taken, but I still think that the device should be protected against supplying it with a "malicious" input voltage, as there are cheap and robust components to do this. The NCP373 for example (http://www.onsemi.com/pub_link/Collateral/NCP373-D.PDF) protects against voltages between -30 to 30 V and is designed exactly with the "faulty USB cable" use case in mind, and the low-volume cost is just 50 cents (large-volume cost is probably much lower). So I think there really is no excuse for letting a faulty 5 $ USB cable destroy your 1000 - 2000 $ device, even if it supplies an input voltage of the wrong polarity.