Parades/protests in the cities in the US require a permit.
There has been an on going battle here in Houston for over a decade between two groups to have a parade on MLK day. At first they would race down to the city and try and get the first permit for the day. And it got so hostile the city stopped issuing permits for parades along that route( MLK Blvd ) because it would be shut down literally all day. There would be an AM parade and an afternoon parade. I don't even know what they do now. I just remember at the time thinking how horrible it was that people were violently fighting over having a parade in memory of a person that was for peace.
- - - Updated - - -
Guess you missed the very first line of the very post of this thread.
Some pretty violent looking photos in that link. Kicking and shoving, people screaming.
- - - Updated - - -
If I don't know something I will say it. I don't have an epeen to protect like you guys.