So, when I was like 18 I made an app for a guy who stole a phone book database in paper and was paying people to pass it to access.
He asked me a program to make it easier to add data, he was paying people to do it one by one to an access db.
So I made that and a module to join all the dbs and check for existing ones (there was no way to join access db back then).
When he told me he didn't want it anymore...
So I deleted the sorce code and gave the binary to an uncle to use as a phone book for work.
Two weeks latter the guy called because he didn't know how to join the dbs. Well the source wasn't lost... I just deleted it and told him that if he had paid my software would take care of it...