It is also true that people who rob businesses are harmful to society. That is completely independent of the terrible outcomes caused by private vigilanteism.
I see, but I don't find a problem with that either though.
Seems no different than crime stoppers, it's usually just a reward for information leading to an arrest, it's not an actual bounty. It's not excluding that, but he's most likely hoping someone who knows the person who stole it will rat for the money.
And I think you'll have to provide examples of the "terrible outcomes caused by private vigilanteism".