This is always the way it is...there are a lot of people who legitimately protest injustice of all kinds. They are often very angry, no doubt with what they consider to be good reason. And they are most often reasonably peaceful and reasonably clear about what it is they are trying to accomplish.
And then there are the "pros." The professional protesters who already own all the accoutrements -- masks, black clothing, etc. -- and who descend from wherever they are to wherever the legitimate grievance is. They are very often the ones responsible for the violence, for the looting and destruction. They usually don't have an agenda that aligns with what the original protest was about -- they are about anarchy, about destruction, about theft, about hatred, about almost everything EXCEPT justice and fair treatment of all.
Those people, I would most dearly love to see rounded up and encouraged to protest whatever they'd care to under armed guard while doing something useful like building roads or picking cotton.