Graffiti and Property Rights

I looked up the defintion of “graffiti” on M-W.com (Merriam-Webster OnLine). The definition is “usu. unauthorized writing or drawing on a public surface”. So my questions are as follows:

  1. What is meant by “public surface”? Is public property such as government buildings qnd structures, or does it also include the outside wall of a private building?
  2. The definition states “usu[ally] unauthorized”, but for graffiti on private property, would an “unauthorized” work of graffiti be per se a violation of property rights?

You have it, even Webster has lost the concept of private property. It is impossible to know who has ownership rights on “public property” so it is impossible to know if graffiti is a violation of this property. But with private property, graffiti is simply vandalism.

Yeah, it would be like calling rape an “unauthorized sexual act”.