A very interesting experiment by a game developer who seeded a pirated version of their game which was not quite the same as the original:
The cracked version is nearly identical to the real thing except for one detail… Initially we thought about telling them their copy is an illegal copy, but instead we didn’t want to pass up the unique opportunity of holding a mirror in front of them and showing them what piracy can do to game developers.
…
If pirates are put through more trouble than genuine customers, maybe more will buy the real game. Sadly, for AAA games it is currently the other way. Customers get the trouble with always-on requirements and intrusive DRM, while pirates can just download and enjoy. A twisted world.
AB's Reflections 