An expert noted that mass murderers Anders Breivik and James Holmes both lacked much of a social media presence, leading to the conclusion, in Slashdot's phrasing, that "not having a Facebook account could be the first sign that you are a mass murderer."
Well shit, think what you will, but this is both stupid... and dangerous. Not everyone likes being watched 24/7. Not everyone wants to be an open book on the internet, me included. I'd wager that it's much more interesting to know people who don't share everything on Facebook, who like to keep their private life just that.