From what I've seen is everything is peaceful during the day time, but after the curfews or when it becomes an unlawful gathering (i.e. blocking interstates etc.) is when police intervene. Which is what they job is supposed to be. The methods used for crowd control are acceptable when things reach the above mentioned criteria. Protests during daylight hours, and not breaking other laws is fully protected by 1st amendment, and I have seen no sign of police missteps in my city during these lawful peaceful demonstrations.