But there is nothing inherent in offering cell phone service as far as locking phones. That's a totally separate issue. I assure you that you could buy an unlocked phone (at full retail) and use it on a network of your choice with an appropriate SIM card.

You just don't get the telco to pay for 2/3rds of your phone when you do that.

They pay 2/3 of the phone for your contract, which has nothing to do with locking or you using someone else's sim card.

This isn't really about cell phones, it's about copyright and how copyright laws apply to physical devices that you own. The fact that the devices in question happen to use public airwaves is incidental. IMHO, I should be able to hack my WiFi-only iPad and my XBox without risking criminal prosecution.

Cell phone locking has absolutely nothing to do with copyright. It is absurd that copyright law applies to unlocking/locking a cell phone.

It doesn't have anything to do with copyright, nor is it illegal. Someone started a rumour and people keep repeating it ad nauseam.