Because you stated "Pavements are differzentiated from roads. As you're so hot on legality, I wonder why you're not more interested in the effective exclusion of pedestrians from road space, which they may use or occupy without breaking any law whatever."
And you responded with questions about anticipated public and police behaviour in the face of hypothetical events that are irrelevant to the thread. Just to clarify, I meant use or occupy not in the sense of hold a demonstration, but in the everyday sense that people use or occupy public spaces in the course of going about their business.