Seems like the cell phone company would deactivate the phone from further use upon notification by the legitimate account holder. Or they can triangulate the position as to where the phone is if it's left on. To re-activate, don't the cell phone companies get any information stored on the phone, such as serial numbers and so on and so forth? Where's the bill of sale if questions arise? Seems like a phone call to the original owner from the cell phone company would clear things up if that was in question.
Why all the fuss and internet drama? Losing or having a cell phone stolen is serious business. The cell phone owner shouldn't have to deal with it past making a single phone call.
Les