Graffiti (singular graffiti or graffito, the latter only used in graffiti archeology) is writing or drawings made on a wall or other surface, usually without permission and within public view. Graffiti ranges from simple written "monikers" to elaborate wall paintings, and has existed since ancient times, with examples dating back to ancient Egypt, ancient Greece, and the Roman Empire. Modern graffiti is a controversial subject. In most countries, marking or painting property without permission is considered vandalism. Modern graffiti began in the New York City subway system and Philadelphia in the early 1970s and later spread to the rest of the United States and throughout the world. Source: Wikipedia (en)