It's wrong not to return a lost item.
Greg is walking down the street when he finds a wallet on the ground that belongs to Jim.
Greg wants to get the wallet off the street.
Greg takes the wallet and looks to find Jim's name before looking his phone number up, so he can notify Jim he found it.
Greg picks up the wallet and throws it in the garbage to get it off the road and prevent someone from taking it.
Jim is delighted and relieved his wallet has been found, and he won't have to go through the hassle of canceling cards.
Jim is stressed out about his lost wallet and is forced to call and cancel all his cards in fear of identity theft.