> Imagine one attacker distracting the victim in a café and the other attacker quickly inserting the Kill stick. Sort of a hardware Denial of Service.
You're in a coffee shop. Wouldn't the attackers just "accidentally" spill coffee on your laptop? Some laptops cope well with water from the top (over the keyboard) but not in the air vents.
> Wouldn't the attackers just "accidentally" spill coffee on your laptop?
The difference is deniability, you can always see that someone killed your laptop with coffee or smashed it with a hammer, with this you wouldn't know until you can examine the circuits.
And even then, power surges do happen. Circuitry get fried from time to time. There is still a level of plausible deniability.
One example: http://www.connectworld.net/syscon/usb_security.html
I am going to research for lockable USB dongles you can insert and remove only with a key.