Some Facebook code leaked online at facebooksecrets.blogspot.com (I prefer not to link directly to the site):
[Blurred]
Later on, Facebook PR chief Brandee Barker stated the following on Techcrunch.com:
“A small fraction of the code that displays Facebook web pages was exposed to a small number of users due to a single
misconfigured web server that was fixed immediately. It was not a security breach and did not compromise user data in any way.
Because the code that was released only powers the Facebook user interface, it offers no useful insight into the inner
workings of Facebook. The reprinting of this code violates several laws and we ask that people not distribute it further.”
So it seems that it was a server misconfiguration (apache / mod_php) or high traffic that led the server to output the code instead of the interpreted page? Would be plausible. But then, if issues like this are known, why don’t you take care of it?
Wasn’t there Sysadmin Day lately? 
Facebook PHP Security Social Web source code Web 2.0 
