Insider threat is an ancient phenomenon. People who betray the trust of those around them have always existed as thieves, embezzlers, spies, saboteurs: the disgruntled. Also ancient is peoples’ tendency to live and work in groups, evolving to operate as an ordered community – as a society. Within society, insider threat is written into Western cultural artefacts (for example, Judas’ betrayal of Jesus) and is recorded across the canon of Western history. Insider threat is endemic to the human condition.