This message was sent to members of the Facebook Developers group this week:
Over the last few weeks we have noticed several developers misleading our users into clicking on links, adding applications and taking actions. While the majority of developers are doing the right thing and playing by the rules, a few arenÃ¢â‚¬â„¢t Ã¢â‚¬â€œ and are creating spam as a result. Going forward, if you are deceptively notifying users or tricking them into taking actions that they wouldnÃ¢â‚¬â„¢t have otherwise taken, we will start blocking these notifications. The bottom line is that if the notifications you send are the result of a genuine action by a Facebook user and that action is truthfully reported to the recipient so they can make an informed decision, you should have no problems. If you do find some notifications blocked, it was probably because this wasnÃ¢â‚¬â„¢t the case and we will be happy to inform you of some best practices by other developers that have prevented this issue.With a lot of people criticizing the MySpace-ification of Facebook, its encouraging to know the service is still attempting to keep it's preppy image.
If you've been blocked by us for deceptive notifications, the error message you will see is - 200 Permissions Error.
The Facebook Platform Team