No not when ever they feel like it, read the 1st amendment again: or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.
I think you may be mistaken about them being there to peaceably assemble.
Did you see the video above? They plan overthrow of the govt.
Armed men. Blocked off the road. Broke into a govt building. Chasing everyone off. Got on CNN and promised to murder anyone that came close. Got on CNN and said they want to overthrow the govt.
What's peaceful about that?