I used to associate the word "hacker" with "badass." It was not a title to be tossed around like the village whore, it was only given to people who had proved themselves with years of hard work, and ingenious or innovative hacks. Becoming a hacker was the equivalent of finding Enlightenment. Any hacker can collaborate, but hackers also stuck me as renegades - people who would build something great with their own two hands.
Hacker culture is probably not something you will find in a company that has just gone public. A public company with as much money invested as Facebook has too much to lose to embrace real hacker culture - which cares nothing for deadlines, rules, managers, filling out wireframes, etc.
I am sure there are plenty of smart people at Facebook, but it all feels a little too rah-rah school spirit, ping pong tables in the break room, silicon valley kool aid, etc etc. Not the seedy basement you expect hackers to infest. :)