Ah, but if I remember correctly, the terms of that OAuth usage explicitly state that while data may be accessed and used, it can't be stored indefinitely (with good reason, sometimes I don't want some app toy to indefinitely store all the information I trust Facebook with). So if a third party uses that API as an export mechanism, their API access should be (rightfully) shut down.
BUT - what if I actually want to export all of my photos into SomeApp.com, and I want to give SomeApp the right to store my photos indefinitely? Is there an API they can use to pull it from Facebook directly?