I have been a member of Facebook for about 4.5 years now. I joined right when they expanded to UC campuses, wayyyy before it was valued at 15 billion dollars. I was just checking out my profile page and it is a PR6! But, it's not indexed. how is that possible? If Google doesn't know about my page, how does it have pagerank?
Are you sure it's not indexed? a while ago Facebook changed their policy so facebook profiles are in google unless you've blocked it in your privacy settings.
I am pretty sure you have to actually opt-in to be indexed. But even then, the page that gets indexed is not the profile page, its another page with just a picture and send message button. Also, just to be certain, i searched for the URL and nothing appeared.