Apple plays what its CEO Steve Jobs once likened to a game of "cat and mouse" with iPhone unlockers and jailbreakers. Jailbreakers, like the iPhone Dev Team, try to release the iPhone from being limited to the official iTunes app store and other firmware restrictions, while unlockers, such as George Hotz, use the jailbreaks and other techniques to unlock the phone, allowing it to run on any hardware-supported network.

Usually the unlockers/jailbreakers seize the day, but occasionally Apple will win a round. Apple has tried many approaches -- everything from "bricking" unlocked iPhones to denying jailbroken iPhones access to the iTunes store -- to halt the spread of unlocking in the U.S. and force people to use AT&T, despite the hardware being capable of working on other carriers such as T-Mobile.

Now, Apple has managed to gain an upper hand over the persistent hackers according to iClarified, thanks to the release of a new bootrom, iBoot-359.3.2. The phone firmware, which shipped on new iPhone 3GSs starting this week, closes previously used doors to exploits.