There is someone on craigslist selling a Brand New Sealed in Box iPhone 4 for $450. I called her and she told me that she works at Bell and she won it in an employee contest, thus she has no receipt. For me, this drew suspicions, how could I tell if it was stolen or not. I heard that if it is stolen there would be no warranty... Also I heard that she can take it back or disable it since she has the serial number... Can anyone help me out, what precautions should I take. This is my first time buying from craigslist and I am very unfamiliar with the process. Thank you!