A friend, in a drunken escapade in college, found a back-door into the university President’s lobby and office. It was an old building with a lot of underground steam tunnels, hidden stairways, etc…
He pinched (stole) large photo of one of the early college Presidents, as a trophy.
The next morning, he realized the consequences of what he had done, swore us to secrecy, and promptly hid the photo far from his campus apartment.
He returned it, anonymously of course, about 15 years later, and also made a pretty large donation to the school
Apparently this sort of thing happens more often than we think!