At Facebook, zero-day exploits, backdoor code bring war games drill to life
  The engineer's computer was compromised using a real zero-day exploit targeting an undisclosed piece of software.

What the diddly ding dong is Facebook doing with real 0-day exploits (besides using them in fire drills)? More importantly HOW did they get their hands on 0-day exploits? And what other exploits do they have/buy/finagle? Is it on a regular basis?