We all encounter people who have disturbing characteristics. They tend to cause social disruption and may even be labeled as evil. These are the members of the Dark Tetrad: Narcissists, non-clinical Psychopaths, Machiavellians and every day Sadists.  These individuals are not rare, are not institutionalized, and may represent a significant portion of society.  This lecture will closely examine the Dark Tetrad, identify their characteristics, give examples of each type and explore how the internet has provided a new platform for their behavior.