I refer to Facebook's "People You May Know" feature as "People I Hate." For some of them, Facebook is quite right--I do know them. And I don't want to be friends.
People You May Know for me is 'Friends of couples you have both of on Facebook'.
e.g. my Romanian coworker and her husband have a lot of friends back in Romania, and apparently an assload of them are on Facebook because Facebook is constantly suggesting them to me.
Likewise, someone's brother or ex or girlfriend or whoever friends me and suddenly Facebook has a huge wealth of people to draw from, and yet it can't figure out that I don't know a 14-year-old girl who lives in Arizona who is only friends with one other person I know.
Facebook's friends-of-friends hack is meant for younger groups of people who have large groups of acquaintances outside of their smaller group of friends - think high schoolers or college kids, where you might actually know that person your friend knows, but you don't have them on FB yet.
In comparison, once people hit 25-30 and their friends are scattered across the country (and they start friending coworkers, etc.) the whole system becomes noise over signal, and it all falls apart.
