A simple erase erases ONLY the volume directory and leaves the data untouched. Granted the data is not as organized as it would be on an HD and therefore much harder to piece together, but given enoughvdesire, time, and money it is potentially recoverable. A 7 pass erase actually overwrites the data cells with alternating patterns of ones and zeros and I don't know if even an NSA level lab could recover it or not. I have read varying opinions on that but all agree someone would really have to want the data.
