I am confused. I thought it was only illegal to unlock the phone when you buy it on the cheap, for the price of extending your contract? They don't want people buying a $600 phone for $200 bucks (for example), unlocking it, then possibly selling it right away. If the carrier sells you the phone for a reduced price, they just want to be sure it is used on their particular network for the contract period.
If you buy the phone at full price or from someone else, and it isn't on contract, you can do whatever you want.
I'm not sure why this pisses people off.
If you want to unlock it, buy it outright.
If you can't afford to buy it outright, you'll have to abide by their rules.
If you don't like their rules, break them and risk consequences, if there are really any.
I love a free country.