Urban graffiti is a major issue for many large cities around the world. These acts of vandalism are difficult to eradicate, as the graffiti often reappears as soon as it is erased. Graffiti is a medium through which its creators communicate their political opinions, spread a message, mark gang territory, assert themselves as marginal artists or simply take part in a delinquent lifestyle.
Strongly combated by affected cities, graffiti is most often a symptom of extensive social problems such as delinquency, poverty and crime. In the United States, Philadelphia and New York were among the first cities to be plagued by this phenomenon. Methods of eradication or control vary from one city to the next, ranging from brutal suppression to training programs for graffiti writers and “anti tag” methods.