Apple warned iPhone owners that unlocking iPhones should be done at your own risk. Using software to unlock an iPhone, would "likely" result in the phone becoming "permanently inoperable" when future software updates were released. The damage caused by unlocking voids the Warranty.
It has been reported that that at least two unlocking programs, iUnlock and Anysim, can cause the iPhone to stop working once the software is updated.FROM APPLE STATEMENT:
Apple has discovered that many of the unauthorized iPhone unlocking programs available on the Internet cause irreparable damage to the iPhone's software, which will likely result in the modified iPhone becoming permanently inoperable when a future Apple-supplied iPhone software update is installed. Apple plans to release the next iPhone software update, containing many new features including the iTunes Wi-Fi Music Store (http://www.itunes.com), later this week.
Apple strongly discourages users from installing unauthorized unlocking programs on their iPhones. Users who make unauthorized modifications to the software on their iPhone violate their iPhone software license agreement and void their warranty. The permanent inability to use an iPhone due to installing unlocking software is not covered under the iPhone's warranty.