Earlier today when Apple announced in-app subscriptions would be available to all they also updated the iOS App Store review guidelines reflecting the change. And it looks like Apple threw in a few additions, one which specifically warns against developers who "cheat the system".
If you attempt to cheat the system (for example, by trying to trick the review process, steal data from users, copy another developer's work, or manipulate the ratings) your apps will be removed from the store and you will be expelled from the developer program.