Having worked on Fraud Detection and Risk Management at eBay previously, I can understand the difficulty in solving this. As it was explained in the video, the fraudsters will want to look like the regular folks as much as possible. I think this is solvable problem. I will not post the features here, My guess FB folks already know how to address this specific aspect of Fraud.

Btw, has anyone had better experience/ROI with FB Mobile app installs ?? How is the effectiveness of those Ads ?