Ok so I bought an iphone 4s brand new sealed and everything from a dude on craigslist. I went to ATT to activate the phone because I have a 3GS, So they told me that the phone couldnt be activated because its registered under another persons number.I have tried also activating it with itunes, with out a SIM and with a SIM, i have even tried formatting it. I dont know who this person is and im not trying to ask them their billing zip code and last four of their ss. I have been to 3 ATT store i have called several times ATT customer service and i have even ended up in the Genuis bar ( which according to them isnt their problem, since its not a hardware issue) a still no luck. I have lost faith with this iphone and i dont know what else to do. Has anyone have has any problems similar to mines or know any solutions?