Here's a crazy idea: why not just let people post notices in public places to promote their events and not bother trying to enforce a bylaw against it at all?
Pretty much for the same reasons that graffiti is illegal: Public places are often private property. Someone has to pay to sandblast or paint over those eyesores. And the broken window theory says crime increases in areas that are not well-maintained.
Here's an idea: let's assume most people aren't idiots. That way we don't have to ban an entire sweep of activities on the basis of a marginal edge case.
