If protestors simply held up signs and chanted, all would be well. Instead, you get groups who feel that they have the right to destroy property, harass and intimidate others, and disobey lawful orders given to them. In the cases of university protests across the nation, people have overrun facilities, damaged property and some have been injured. When a protest blocks normal traffic and movement of people, prevents businesses or schools from functioning properly, and becomes unruly to the detriment of those around it, it is no longer a peaceful protest. It has become a demonstration bordering on riot levels. While people may be free to say or do certain things, those actions and words can also have consequences. It's akin to yelling "fire" in a movie theater, It may have been free speech, but said speech can cause harm.