http://gameological.com/2013/05/inventory-9-games-with-creat... (it is the first one)
More details & discussion from Game Dev Tycoon's developer blog: http://www.greenheartgames.com/2013/04/29/what-happens-when-...
So you're balancing making it hard for crackers to detect, and easy enough for players to encounter that shift behavior.
[1] http://www.quartertothree.com/game-talk/showthread.php?42663...
With non-gaming software the situation is completely different. When a cracked version craps out the prevailing sentiment is always that it was a bad crack. Always.
I'm wondering why there isn't a service that lets you search for people encountering your crack-penalty. A really sneaky company would disguise itself as a hacker group, then offer a copy of the game that doesn't have that "bug." (But has another one.)