Earlier quoted context omitted.
"Look, just because it's in your pocket and you get to use it as soon as you leave the store does not mean you own it." So who owns it? When last I checked, there was no line of credit, I am allowed to sell the phone to someone else without informing the carrier, and I am responsible for repairing any damage or replacing the phone if it is rendered non-functional. It sounds like I paid the carrier's price, signed a c…
Why don't you read your contract and pay particular attention to the bit where it talks about transfer of title? As someone who doesn't sign these kinds of contracts and hasn't for years, I'm not sure what the exact position of the carrier is without downloading and analyzing a phone contract, which I don't feel like doing right now. The differences from leasing a car are for obvious reasons. If you don't make the pa…
More like you're wrong, and are just assuming no one will take the time to read a contract and call you on it.
I just read through the T-Mobile contract (http://www.t-mobile.com/Templates/Popup.aspx?PAsset=Ftr_Ftr_...), and there is no mention of title at all. They do try to restrict what you can do with your device while it is on their network (including prohibiting you from "modifying the device", which should include unlocking), but nowhere do they claim ownership of the device.
The phone is not loaned/leased to you. There is no lien on it. The carrier has no recourse to repossess the phone. The early termination fee is there, of course, but is entirely unrelated from a contractual point of view. If you break your contract, they have the right and ability to collect the early termination fee, and nothing else.
As an aside, I'm not sure why you'd consider it so impractical for the carrier to repossess the phone if someone breaks contract. It's certainly feasible, and they could likely refurb and resell the phone for something on the order of the early termination fee. But yes, that would take more effort than sending a bill, so they have chosen not to consider the phone on loan. It's yours, contract or not.
But none of this is particularly relevant. The question at hand is about whether or not unlocking your phone is a DMCA violation and thus a criminal act. Depending on the particular carrier, it may or may not be a violation of your contract to unlock your phone, but that should be a civil matter, not a criminal one.
Why are you so hell-bent on ceding power to companies that have been granted mono/duopolies by the government, and are making use of a precious public resource (radio spectrum)? Do you seriously care so little for your rights as a customer -- hell, as a human being -- that you'd prefer that modifying a device you own (yes, own) is a felony? I just don't understand why anyone would side with one of the carriers... ever. For the most part they are as anti-consumer as companies can be. Individuals have little way to right that imbalance without government intervention.