My understanding of power surges is that they can simultaneously damage anything that's plugged in to AC power.
My question is whether a drive that's connected to the computer via USB (only) is better protected than a drive that has its own power supply. My thinking is that there are so many components between the external drive and the computer's power that the chain may provide a degree of surge protection. But, that's only a guess--I don't actually know.
Does anyone actually know how the electrical process of surge works and whether there have been any laboratory experiments?
(PLEASE no answers of the form "you need all the protection you can get" or "you need to protect anyway". I'm not asking for advice about protection from surge.)