It looks like starting from today, Sprint will be officially locking their iPhone 4S’s, according to a leaked internal document. The unlocking will occur when the phone is activated and will be a background process that the user will not be aware of. Strange enough it appears that this lock update will not affect customers who have bought the iPhone 4S prior to the 11th of November 2011, so if you were quick enough, you will be able to enjoy an unlocked SIM slot on your iPhone 4S.
The good news for those who are hoping to unlock their iPhone 4S’ after the 11th of November, Sprint will still provide that service in the future for customers who are in good standing with the carrier. By that we assume that customers who have paid all their bills and have no outstanding payments or defaults with the carrier.