I think that if Apple was to create a new version of the OS that prevents the iPhone/iPod from being restored by someone else's computer. They would essentially program a list of all computers that the iPhone is allowed to be restored by. Even in recovery/DFU mode, it would check to see if the computer restoring it was an authorized computer. Upon firmware update, the iPhone would immediately remember a unique computer ID. Can't restore your iPhone using an authorized computer? No problem, just take it to the Apple Store, prove the iTouch is yours -- their computers would be on the list by default.