It makes for funny interactions in my experience. Bunch of people coordinate to gather in some park, but dont actually technically start any protest or block the street. Then when the cops arrive or just happen to come by (often they already know because they look at public social media) someone walks up to them saying “I hereby declare the forming of a protest” and then we just start. Most experienced officers know thats how it works, but sometimes newbies get all confused and call their superiors.