Who is behind Facebook?

This piece about who put the money behind Facebook raises a number of interesting questions.

The CIA, through In-Q-Tel, has a large investment in Facebook. Does this mean that the CIA is actively using Facebook to spy on US citizens? Why else would they be interested in such a tool?

I know some people that don't use Facebook because of questions like these. But seriously folks, what could the government do knowing that your favorite movie is "Grease 2"? Besides laugh, of course. Nothing. Thats why I'm not worried.