"The Strange Return of Gyges' Ring" in Lessons From The Identity Trail: Anonymity, Privacy and Identity in a Networked Society (New York: Oxford University Press, 2009)

Book II of Plato’s Republic tells the story of a Lydian shepherd who stumbles upon the ancient Ring of Gyges that has the power to make him invisible. In the story, the shepherd uses the ring to gain secret access to the castle where he kills the king and overthrows the kingdom. Plato uses this story to pose the classic philosophical question: why be moral if one can act with impunity?