Word on the Street

I'm not certain that I am remembering this correctly, but I recall my mother suggesting that graffiti is a sign of poor toilet training. Maybe this isn't her quote, but it certainly rings with motherly authority. Regardless of its origin, these words played in my head as I rode my bike past the neighborhood park and noticed that the sign at the gate now included the admonition: "This park is owned by the Dubbas."
Well, how do you like that? Apparently any barely literate person with a Sharpie can take ownership of public property by scrawling their barely legible intent wherever the mood strikes them. I confess that it bothered me first on the hoodlum level - Who are the "Dubbas" and should I be concerned about them doing anything more than defacing public property? This is a park that my son, wife, dog and I have gone to play on occasion, and for the first few months the playstructure remained pristine. Free from any young toughs looking to establish their domain by scribbling on any moderately smooth surface with a permanent marker. Then the flurry of "tagging" began. If there's one, there will be a dozen - highly reminiscent of the way my dog stops to mark her territory as we move through the neighborhood.
The lurking delinquent factor is just the beginning though. I know that graffiti can be art. Someone is going around our neighborhood and spraypainting large green cartoonish birds on underpasses and sidewalks. Across town there is a series of odd versions of the street-crossing silhouette: one holding a candle, another sinking in a pool of water. We see boxcars with billboard sized tags with color and shading that make the freight yard come alive. Are these acts of vandalism, or public art? I'm reasonably certain that the bird person would probably get in more trouble just because he or she chose to work in such a large format.
Maybe I'm just fussy about the penmanship, but I'm always happy when they spell their threats correctly.