Help with a moral dilemma

[GGD]

N-OS X-tasy! wrote:
No, it wouldn't. U.S. mail order regulations state that a person is entitled to keep any item mistakenly shipped to him/her.

Here's the actual regulation http://codes.lp.findlaw.com/uscode/39/IV/30/3009

It needs to be identified as a gift to the recipient (not just any random miss-delivered package).

All such merchandise shall
have attached to it a clear and conspicuous statement informing the
recipient that he may treat the merchandise as a gift to him and
has the right to retain, use, discard, or dispose of it in any
manner he sees fit without any obligation whatsoever to the sender.

N-OS X-tasy! wrote:
Theft is taking something from a party without their knowledge or consent. If the party sends you something, however - even mistakenly - it is not theft.

You often see news stories of cases where a bank mistake deposits funds in someone's account, and they decide that it's now their money and spend it. It never ends well for those people.