The source code for the front page of the widely used social networking site Facebook.com has been leaked. If you want to see more take a look at the following post at http://facebooksecrets.blogspot.com/2007/08/facebook-home-page-code.html
It seems there are people already getting Cease & Desist letters from Facebook as they attempt to use this newly released information.
UPDATE: Google was forced to bring the Facebooksecrets blog down due to DMCA infringement. The Facebook Secrets people have started a new blog here though 
