What about this: seeing the house has no lock, opening the door, going inside, counting the money in the owners wallet, putting it back, then reporting that "Anyone could steal $300 from that guy".
If I were that guy I would be very happy that someone informed me about the vulnerability of my wallet. I would definitely thank them and invite them for tea. Reporting them to police would be the last thing on my mind.
What about this: seeing the house has no lock, opening the door, going inside, counting the money in the owners wallet, putting it back, then reporting that "Anyone could steal $300 from that guy".