a phone is a tool that will decode the information on your SIM card provider and contract that you already pay for antenna services.
if a company sells you a phone along with the contract then it is called BUSINESS or MARKETTING since they do business with manufacturers so they can get the Phones cheaper and make a little more profit. there is no rule about unlocking phones, especially not China Clones since they are nothing more than pieces of metal and plastic glued togheter. Shame they look like the real deal tho!
Companies like AT&T for example knows that people will use any kind of phone. when you buy the SIM card, what you do after is up to you, cause YOU are the one who will pay for antenna usage, not them!
EDIT: kinda misread the topic, still what i said kinda applies to the thread.... but yea, unlocking iPhones can be considered illegal to Apple, but not necessarly to the Phone Company you will use it with later on. cause you paid for the item as a whole, you should be using it the way you want... too bad corporations don't allow this cause if they did, then they couldn't afford sending their childrens to Harvard anymore.