The Sims world is under assault (from SecurityFocus:
Entire neighborhoods of Sims are being mysteriously graced with eternal youth, while some characters are finding all their needs fulfilled by a single shot of magic espresso. Others no longer need to empty the toilet after potty training their toddler. Some Sims are being abducted by aliens when they glance through their telescope — every time, instead of just occasionally, which is normal.
What nobody had realized was that hacked objects or behaviors would be transferred with the house, and would supersede the game’s original functionality for anyone who installed it. So if you download a house with a magic espresso machine in the kitchen, all of your espresso machines in all of your Sims houses and neighborhoods will become magic. If the house came from a game that has the “No Jealousy” patch installed, your game will henceforth be free of the green-eyed monster as well.
If you then export one of your houses and share it, anyone who installs it will also be gifted with special java and open relationships. And so on. As a user downloads and uploads more houses, the hacks accumulate in the game like spyware.