this piece, Henry Copeland attempts to suss out the motives of these buxom "Bimbots". His conclusions are profoundly non-surprising:
My guess is that somebody is setting up Facebook accounts with nonexistent (or hired) attractive women, and sending out large numbers of friend requests to guys with the hope that many will accept the request. (For all I know, similar requests, with attractive guys, are being sent to women.) Once you accept their friend request, they gain access to a lot of information about you.
Even after Facebook tightened up its privacy settings, it seems clear that people are blithely sharing way too much of their lives with people they haven’t fully vetted. And it seems likely that our conversations are being spied on, recorded and analyzed, either by folks from China or by corporate sleuths hiding behind seductive masks to track and influence conversations about their clients, customers and competitors.