The Crowd: A Study of the Popular Mind, written by Gustave Le Bon and published in 1895, is considered a seminal work in the field of crowd psychology. While it was not the first work on the subject, it was the first to propose that a crowd is itself a distinct entity that emerges from an assemblage of persons that possesses a “collective unconsciousness” and a “magnetic influence” that changes the behavior of it constituents until it becomes governed by a “group mind”.  This influence robs each of its individual members of their opinions, values and beliefs in the process. Le Bon states: "An individual in a crowd is a grain of sand amid other grains of sand, which the wind stirs up at will".  Le Bon posits three key processes at play: anonymity, contagion, and suggestibility.  Anonymity imparts a sense of invincibility and a loss of personal responsibility that causes a devolution of the individual to the primitive, emotional, and unreasoning instinctual drives.Contagion enables the rapid spread of ideas and behaviors in the group and the sacrifice of personal interests to the collective interest. Suggestibility is the mechanism of the contagion, used by the strong voices to impart ideas that guide the contagion of behavior.  Such leaders Le Bon describes as “usually men of action rather than of words. They are not gifted with keen foresight... They are especially recruited from the ranks of those morbidly nervous excitable half-deranged persons who are bordering on madness."  The book became an instant bestseller upon publication and was translated in nineteen languages within a year. Its message is especially intriguing today in light of the phenomena observed in virtual groups that emerge on social media.