Yup, violence against people and property in this context is almost always counterproductive. It drives people away from the cause, confuses the issue, and usually ends up hurting people not at fault for the issue being protested on.
Not only that, but trying to out-do the government and State on violence is like trying to beat Keith Richard's record for drug use... highly likely you will not only fail, but will also not survive the attempt. 😉