>      Somebody else made the comment that USB is designed to protect
> against this.  I'd just like to say it is impossible to prevent a
> device from doing something it shouldn't and killing the bus,
Of course you can't prevent a device from frying other devices
on the bus by injecting lightning into the bus. :-)
But USB is pretty well protected against software faults
in the devices since the bus really forms a tree and the
host controller can shut off the port to the offending device.
(Some of this is even built in to the operation of a hub.)

      -- Lennart