It's quite clear what the limits are for protests in Ottawa. There are dozens to hundreds of protesters in Ottawa continuously. There are regularly protests of thousands of people. If you want to block the road, you get a parade permit which is easy to get. You can shout as long as you want, but if you use an amplifier the police will eventually take it away from you. You can carry obnoxious signs. Blocked roads because of protests are an annoying fact of life in Ottawa. But you shrug and move on, it's a cost of living/working in downtown Ottawa. I've never seen a protest block the road for more than 4 hours.