"Individual users are already allowed to unlock their own phones under an exemption to the Digital Millennium Copyright Act (DMCA) that the U.S. Copyright Office issued last November. The exemption, in force for three years, applies to 'computer programs...that enable wireless telephone handsets to connect to a wireless telephone communication network, when circumvention is accomplished for the sole purpose of lawfully connecting to a wireless telephone communication network.'"
Why would an exemption even be needed -- why should copyright law be involved with this argument. Call me a simpleton, but it's obvious that someone who shells out $500 for an iPhone is not renting it from AT&T or Apple. Once I take it home, I can use it the way I want. I can turn it into a gun. I can turn it into a candle holder. I can serve pancakes on it. I can prop up an uneven table. And, if I want to crack it open and futz with its insides, I should be allowed to do that.
Or let's try a different analogy. If I bought a Toyota Prius and brought it home and stuck in a Dodge Hemi, would anyone think for a second that Toyota would have a legal right to stop me?