One more reason not to talk to strangers, at least on Facebook. They’re launching a new feature called social authentication, and if your friends list is full of people you don’t actually know, you could be locked out of your account:

Instead of showing you a traditional captcha on Facebook, one of the ways we may help verify your identity is through social authentication. We will show you a few pictures of your friends and ask you to name the person in those photos. Hackers halfway across the world might know your password, but they don’t know who your friends are.

The problem with this, of course, is that if you may not know who your friends are, either. +1 for my new favourite Gmail filter.