Facebook has started to allow users to create their own apps. If you're a member, you may have noticed this by the massive number of application requests you have started receiving. The problem is, these apps by default won't go through much of a vetting process. This allows sites such as this one, to find all of the nasty holes each new app pokes into Facebook. If this doesn't worry you because you aren't using any of the broken apps, it should, because many of these apps can be abused to direct attacks against people who don't use the apps. Given that much of Facebook involves sending content from one user to another (i.e. propagation), this has the potential for a self-propagating malware ala the MySpace "Samy" worm.