but I remembered that most of the physical access hacks would not be possible if the disk is encrypted.. which then makes this kind of hack enormously attractive.
The antenna idea can be extended to be a piece of hardware with the interference device built-in (piezo or whatever) which communicates with the external world with any wireless medium and then the attacker can trigger the interference remotely. This, plus a website controlled by the hacker which the victim is scammed to visit can be enough to make it viable.