nonprofiteer writes "Researchers presenting at Defcon next week have developed a psychopathy prediction model for Twitter. It analyzes linguistic tells to rate users' levels of narcissism, machiavellianism and other similarities to Patrick Bateman. 'The FBI could use this to flag potential wrongdoers, but I think it's much more compelling for psychologists to use to understand large communities of people,' says Chris Sumner of the Online Privacy Foundation. Some of the Twitter clues: Curse words. Angry responses to other people, including swearing and use of the word "hate." Using the word "we." Using periods. Using filler words such as 'blah' and 'I mean' and 'um.' So, um, yeah."