Apple stated on Monday that "unauthorized modifications to the software on their iPhone violate their iPhone software license agreement and void their warranty." Accordingly, there is a difficult legal question about whether a simple SIM unlock prohibition violates the Magnuson-Moss Warranty Act, according to Phonenews.

"The Magnuson-Moss Warranty Act states that Apple cannot void a warranty for a product with third-party enhancements or modifications to their product. The only exception to this rule is if Apple can determine that the modification or enhancement is responsible damaging the product in question," wrote Christopher Price.

Due to the way Apple designed the iPhone, SIM unlocking requires a change to Apple’s baseband firmware. While unorthodox, it appears to be the only way to unlock the iPhone. Unless Apple can prove that modifying this firmware damages the iPhone, their statement appears to violate the Warranty Act. "It’s no different from putting a third-party part in a car that does not damage or inhibit any other part of the car. Furthermore, it is valid and has been ruled as not a DMCA violation by the U.S. Copyright Office, so there is no tainted hand argument either," Mr. Price observed.

There are further complications. If the unlocking procedure can be reversed without damage to the iPhone, Apple could be compelled to provide warranty service under federal law.

All this will, no doubt, be settled in court actions. However, precedent with mobile phone unlocking and warranty protection law appear to be coming down on the side of the consumer -- for now.