Has this been done somewhere?
Any other ways to make it look better than tearing it down? Whole bunch of fake glass?
Graffiti is vandalism. It is not traditional, and it’s not art. It’s a crime; there is no exception unless it’s done on private property with permission from the property owner.
Whether a painting is art doesn’t depend on who owns the canvas.
You’re right, but you have to draw the line somewhere. If someone decides to light a building on fire and call it “performance art,” nobody considers it anything but a crime. If someone spray-paints a vulgarity on the side of a school, few would call that “art,” but a mural on the side of a concrete wall is “street art.” The subject matter and the quality of the painting doesn’t make the determination between art and vandalism; it’s just vandalism.
Imagine someone buys the Mona Lisa and declares that its not art and da Vinci grafittied their privately owned piece of canvas. Artists around the globe in shambles.