As the world experiences social unrest, polarization, and faces complex challenges, citizens are taking to the squares and streets to demand change. From climate change protests to far-right extremism, social movements are mobilizing around the key social and political issues of our times. In this extensively revised and updated book, the author offers a cutting-edge and original analysis to generate new insights into 21st Century social movements in a globalized world. Written in clear and accessible language, this book will appeal to both students new to the field and established scholars. Drawing on a wealth of examples from around the world, from Anonymous and Occupy Wall Street to Wikileaks, the Tea Party, and the Zapatistas, it develops a compelling framework with which to understand the important role movements play in contemporary politics. This expanded and revised second edition includes a comprehensive overview of social movement theory, a new chapter on "Movements on the Right", a wider discussion of Information and Communication Technologies and Media - including new sections on "hacktivism" and "leaktivism" -and up-to-date case studies and references.