How about you just don't get violent? There is an idea... I know it is hard for some to follow so I will try and explain. You show up to the protest and you walk and yell with or without a sign. Feel free to say whatever you want that isn't illegal. You don't block traffic and you don't attack other people and/or buildings. At these peaceful protests you shouldn't really need any type of flammable liquids, explosives, rocks, bricks, or any other type of hard device that can be thrown. You can bring your phone if you want and film the police standing around doing nothing(as long as you stay non violent).