Group violence is a difficult thing to control. Mob mentality can quickly get out of control. The sense of anonymity an individual experiences in a crowd could lead them to do things they would never do in a one-on-one situation. In today's political landscape, there can even be professional crowd agitators implanted within the protest to try and incite violence. 

You have to plan. Whether participating in a peaceful protest gone wrong or simply traveling through the wrong place at the wrong time, you need to be prepared for a worst-case scenario. Try to mentally think through possible scenarios before you are presented with them. Make sure you have shoes that you can move swiftly in. For more details on items you should carry, visit Traveling Through Hostile Territory. 

In the best case, you will be with a group. You must connect with someone. Being alone in a crowd is not where you want to be. Lock arms with your group or grab one another's belts so you do not get separated. If you are on your own, try to move with the flow  of the crowd while slowly making your way to the edge. In a worst-case scenario, throw yourself at a police officer. You may get beaten, but you will get removed from the crowd. For more information on handling a crowd, visit Crowd Control. 

You need to stay calm and in control of yourself. You may be tempted to join in with the mob, but if you don't support their activities, do not compromise your values for the sake of the mob. Try to remove yourself from the situation. If you have a group behind you, ask questions of your fellow protestors. Does everyone support the violence that a few may be calling for? When engaging, try to repeat to the individual what they are saying to keep the conversation focused. Arguments can quickly spiral into anger about everything except what started the argument. Try to stay focused in a positive way.

Peaceful protests are an essential part of the democratic process. Making sure that the protest stays peaceful is the responsibility of each participant. The best way to stop group violence is to prevent it from happening in the first place.