Okay so I'm quite familiar with factory unlocks and jailbreaks and things of that nature. However a friend of mine told me the other day that his friend can use his phone on any carrier, and he doesn't pay a monthly bill. He told me he had something like a "blank" SIM card and that it allowed him to tap into the strongest network available without them (the carrier) knowing. Unlimited everything, all the time, 100% for free. Needless to say I was thinking "bullsh**" the entire time. But to be honest this guy has a history of doing very illegal things so I wouldn't put it past him. Is something like this even possible? I have no interest in doing so whatsoever. But I want to know how it all works.