How to spot a sociopath - 10 red flags that could save you from being swept under the influence of a charismatic nut job
http://www.naturalnews.com/036112_sociopaths_cults_influence.html
Some are a bit more subtle. You can't find out for months, at times. I've known enough of them in my life. Another reason to be an isolationist. As for those few individuals I do associate with, I pick my own liabilities; thank you.