There seems to be some misunderstandings in this thread. Anyone who has paid off their device can already get it unlocked from all the major carriers for free.

There seems to be some misunderstandings in this thread. Anyone who has paid off their device can already get it unlocked from all the major carriers for free. 99% of the unlocks of this guy and similar services perform are for phones obtained by theft or fraud. They are either robbed from T-Mobile stores or they are obtained by "credit muling." Credit muling is where various sketchy people round up homeless or desperate people who need cash to go into cell phone stores and get as many phones as they can on credit with no intention of paying the phone off. The recruiters then take the phones and pay the "mules" a nominal fee like $100-200. This fraud costs carriers billions of dollars each year and makes everyone's cell phones bills higher.