A friend of mine (who shall remain nameless) alerted me to one developer's unique attempt at stopping the piracy of their software. The application is called USB Overdrive and is a small utility for mapping actions to any USB mouse, trackpad, joystick or gamepad on the Mac.
Since fighting piracy is often a cat and mouse game involving constant updates on the part of the developer, Alessandro Levi Montalcini has given up trying. Instead, if you enter in a pirated code, you're told in no uncertain terms that what you're doing is wrong.
The developer uses guilt as his weapon. And as many a mother knows, guilt works.
I especially like that the confirmation button is labeled "Shame On Me", forcing the user to stop and think about the consequences of their actions before continuing. Although, honestly, if he just dropped his price to $10 instead of $20 it might make all the difference.