I loved
this piece on ComputerWorld so much (and it gave me the title to the post) so I've stolen it (sorry, it is of course "research")
I'm going to tell you exactly how someone can trick you into thinking they're your friend. Now, before you send me hate mail for revealing this deep, dark secret, let me assure you that the scammers, crooks, predators, stalkers and identity thieves are already aware of this trick. It works only because the public is not aware of it. If you're scamming someone, here's what you'd do:
Step 1: Request to be "friends" with a dozen strangers on MySpace. Let's say half of them accept. Collect a list of all their friends.
Step 2: Go to Facebook and search for those six people. Let's say you find four of them also on Facebook. Request to be their friends on Facebook. All accept because you're already an established friend.
Step 3: Now compare the MySpace friends against the Facebook friends. Generate a list of people that are on MySpace but are not on Facebook. Grab the photos and profile data on those people from MySpace and use it to create false but convincing profiles on Facebook. Send "friend" requests to your victims on Facebook.
As a bonus, others who are friends of both your victims and your fake self will contact you to be friends and, of course, you'll accept. In fact, Facebook itself will suggest you as a friend to those people.
A prediction from the article - Identity fraud will be so rampant that Cellphone numbers will be required to set up profiles on Facebook by mid 2009
Marvellous...now, who shall I be today