But, when it comes to policing behavior in public spaces, few if any people have clear authority of the sort found in private spaces, of the sort that the owner of a restaurant has. We can see the difference between public spaces and private spaces in another light if we consider anonymity, the condition in which the identity of a person is not known. Anonymity is for the most part, I think, a feature of public spaces. Private property owners always have the right to know who you are if you are in their space. Or, they may be willing to accept not knowing your identity provided they have some other assurance that your behavior in their space is somehow constrained.
Public spaces are spaces in which a person can escape being known.
Public spaces, by their very existence, provide wrongdoers, people who would suffer ostracism in privates spaces, with a way to escape a history of wrongdoing. And public spaces provide wrongdoers a way to travel into a new community where they might receive, once again, the benefit of the doubt as honest persons. Another example here has to do with body language and rude behavior regarding pressing into the space of another person. I am sometimes annoyed by the behavior of some drivers on the public roads. This might be tailgating, or flashing lights to demand passage, or cutting me off.