Wow. This guy reminds me of an intern that we tried to hire a few companies ago. Smart kid, finally finished school and the decided that the world owed "him". He tried to get us to change our benefit policy to suit his needs more amongst other demands. Needless to say we passed on him. Seems he had a hard time finding a job for a few months as well...
Seriously, Facebook does not work for you and with the popularity of Facebook this type of behaviour is not unheard of. I have worked at places where it has taken up to 6 months to hire a person due to the interviews, background checks, etc. Recruiters often have hundreds of positions on the go, so expecting personalized attention for each candidate is unlikely unless it is for a high profile position. Oh, and they didn't stick to your schedule? So sorry! Sometimes things don't work out, and both sides have to be flexible. Also expecting Facebook to be flexible when they gave you three months to create an opening is asinine!
While I am tempted to go after him for the BS he felt regarding not being prepared because they changed the interview schedule, etc, I can only hope that Facebook reads his post and puts him on a DNH (do not hire) list. Such high expectations for a simple development position at a large organization like Facebook is insane. This is a classic example of why IT people are viewed as either basement dwellers, anti-social individuals or people who are tripping over their own egos. Come on, it is a development job at a big name company. We have seen hundreds of these stories, both good and bad, over the years from a bunch of other orgs.
So you had a bad interview. Most of us have had at least one in our careers. Get over it. Learn from your mistakes and move on. Oh and dear Slashdot editors? C'mon, we really do expect better.