I might be one of the few here who has a facebook account with 0 friends and never really use it. So the results are very interesting as they contain people who I know but do not interact with. Some of them must be from profile searches I have performed but I cannot explain the others. I am inclined to believe they must be incorporating 'other users behavior on the site'.
Remember when the mydoom worm took down google for a bit due to widespread and distributed searches for itself/targets? I wonder if database resources are infinite?
Thanks for this, I am now also having some thoughts.