Ya know, I am a strong advocate for peaceful protest. I, of all people, (a Vietnam-era hippie) would never condemn a person for protesting against something they feel strongly about. I'd even condone a bit of peaceful civil disobedience.
But I wonder, how many of these people rioting and looting actually give a damn about Michael Brown? How many actually knew the kid? How many actually are on the streets because of the incident, what happened, how things happened? Maybe those that aren't out on summer vacation from school or college would all be better served to take the time they're spending and learn a trade, get a job. And if these are school/college students, now is the perfect time to learn how to make a difference by going about it the right way.
That said, you want to do something, you want to make an impact? There are no laws against peaceful protest. Do it right. This sort of craziness is just trivializing Michael Brown's death, disrespecting him and his family and creating an unwanted legacy for them.