Joel Hodge is a senior lecturer in the School of Theology at the Australian Catholic University, in Melbourne. He is the author of "Violence in the Name of God: The Militant Jihadist Response to Modernity" and "Resisting Violence and Victimisation: Christian Faith and Solidarity in East Timor."
We know from history that engaging in violence only causes more problems. So why do police and protesters still do it? René Girard had an answer: imitative behavior.