Cool [DISCUSSION] Edward Snowden's Claims

Hey XDAers,

I recently watch NBC's "Inside the Mind of Edward Snowden" where he claimed, in reference to phones being turned on remotely, that "They can absolutely turn them on with the power turned off to the device."

My question for you is...how?! I simply do not understand how this could ever be possible. That implies that the radio is on, or can be powered through some type of remote signal, or that it has some type of internal battery that keeps the radio active.

Anybody have any real insight or thoughts on this?