I bought an iPhone 4S from craigslist. I've had it for awhile now and its been working fine. I chatted with AT&T today to try and see if I'm eligible to have it unlocked. He said OK and asked for my IMEI # and then said this: "The unlock code for this device is unavailable due to security restrictions based on the device's history. You may want to return the device and/or provide feedback to the seller. Care should be taken when purchasing devices from non-authorized sources as no validation can be made as to the history of such devices." I asked to elaborate a little bit on the security restrictions. Reply I get: "As a security measure the information is restricted as proprietary information" Does this mean the iPhone was stolen or something? I asked who I could talk to get this information but he kept saying they/he cant say. ????