If I found a wad of money on the ground and you picked it up but it’s not yours should you take it and run or should you turn it in? If i where you i would turn it in so no it is not yours  to keep. Lets say you saw a pretty decent iphone4 and you where convinsed that you where going to buy it.Well do what the golden rule says if you give it back them they will give it back to you.