I lived in Mexico City downtown for 15 years. If you don't know if there is a problem anywhere in the country, people would come to Mexico City main plaza to protest. Many peaceful protests never really achieve anything, others utterly violent neither. I witnessed farmers being beat up by the police, women and kids fighting riot police and building destruction. One common element is that certain police officers are aggressive by nature and suddenly get a free card to hurt people.
I agree with the article, communication is key. In many protests I believe there is a lack of miscommunication in all parties, and others are not well planned or are infiltrated to diminish the reason of the protest. Some groups advocate for violence as the only way to be heard (which in some cases is a valid reason, e.g. fascism) but destroying normal people business vs government Infrastructure I don't think should be permitted