The main theme of this book is a sociological and psychological examination of crowd behaviour and people power. Written for the general public, it draws on a century of fieldwork, and brings together the opinions and guidance of many scientists eminent in their field to give modern-day insights to this traditional area of interest. Nowadays, crowds respond in different ways to the many types of leaders: politicians, teachers, preachers, and the stirrers of public conscience, as well as anybody in the position to influence crowds in times of social strife. The social media now give great power to individuals, enabling a single person to influence people worldwide.