Actually, the data is encrypted firstly with a per-device key that is unique to the phone and unable to be accessed directly (unless you want to go decapping ch

Actually, the data is encrypted firstly with a per-device key that is unique to the phone and unable to be accessed directly (unless you want to go decapping chips), then additionally with a hash of your pin or password. A copy of the data is useless unless you can get to it in an already unlocked state. An erase firstly deletes the encryption key entirely then begins a secure erase in the background.