This is not a particularly new attack. It's been used for years against simpler devices, especially where you can access the flash chip and force it's write protect on.
When BT Cellnet mobiles came out.
http://i.ebayimg.com/images/i/351317080153-0-1/s-l1000.jpg
If sending an SMS, you pulled out the battery, you'd get it for free, a bit annoying but still a cool trick when you were on PAYG.