Someone apparently has the entire source code for the Web site Facebook. By "source code", I mean the things that make the site run - how are searches done, how profile loads are done...all the back end programming (in this case, done in PHP).
For you programmers out there, it looks like they're not really using object oriented code, which many would look at as a "no-no" these days.
This opens Facebook up for all sorts of possible hacking attacks, and it also opens
Was it an insider? A hacker? Former employee? No one knows at this point.
The blog which is posting code
Article about it