apparently I bought a Canadian iPhone 5 off Craigslist yesterday. The guy didn't have the box and so I tested it to see if it was an att iPhone. well, it did work with my att sim. I wanted to unlock it through one of those eBay sellers and to my surprise it says it isn't an att phone. researching it more with the model number, it falls under Canada list. not sure which carrier but it definitely is locked to one of the Canadian carriers. Would someone enlighten me because I thought if it was locked to one carrier it can't be used with another carrier? my att sim works with it but not my tmobile? anyone know where I can factory unlock it?