Graffiti has a long history. There are many examples from the history of human cultures of signs and symbols left on walls as remnants of human presence. However, the origins of modern graffiti reside in the explosion of creative activity associated with the development of urban cultural expression among marginalized individuals, groups, and communities in the United States in the late 1960s and early 1970s. Graffiti has expanded in form and content as well as geography to become an almost universal urban phenomenon. It is a ubiquitous feature of cities and an adornment of the modern urban landscape. It has developed beyond its original expression and identification with lettering and spray paint to now encompass a range of media and practices that are associated with street art.
Graffiti in particular, but also street art, has engendered contrasting opinions and reactions about its effect, meaning, and value. It elicits a variety of responses both positive and negative. Is it art or is it crime? Is it a creative expression or resistance to dominant urban design discourses and management? Is it vandalism? Is it the result of deviant youthful and antisocial behavior? It has been linked to urban decay and community decline as well as regeneration and gentrification. Graffiti writers and street artists have been criminalized, while others have been lauded and promoted within the commodified world of the art market. The popularity and spread of graffiti as a global phenomenon have led to an increasing academic, artistic, and practitioner literature on graffiti that covers a range of issues, perspectives, and approaches (identity, youth, subculture, gender, antisocial behavior, vandalism, gangs, territoriality, policing and crime, urban art, aesthetics, commodification, etc.). The worlds of graffiti and street art are therefore complex and have provoked debate, conflict and response from those who view them as forms of urban blight as well as from those who perceive them as an expression of (sub)cultural creativity and representative of urban vibrancy and dynamism. The study of who does graffiti and street art, as well as why, where, and when they do graffiti and street art, can help develop our understanding of the competing and contrasting experiences and uses of the city, of urban space, of culture, of design, and of governance. Graffiti is therefore also the focus for social policy initiatives aimed at youth and urban/community regeneration as well as the development and exercise of criminal justice strategies.