Unauthorized graffiti art is considered vandalism. When it is painted without the consent of the property owner, graffiti is considered criminal damage in the legal sense, as it is the defacement of private or public property.
As of 2014, graffiti art, sometimes referred to as urban art, street art or mural art, is gaining recognition and legitimacy within the art world and is being included in modern art galleries and auctions. Although it may be legitimized, it is considered vandalism unless it has been authorized by the property owner. In fact, some cities take a hard-line stance against any form of graffiti, whether it is gang graffiti or public art.