Despite the controversy, street art has now assumed the role of a relevant artistic form in modern society. Appearing in the United States during the 1960s, the street art has spread to Europe as an underground phenomenon, but in recent times its protagonists have taken on international fame such as Shepard Fairey, Swoon, Invader or Banksy. Within a multifaceted and discussed phenomenon, street art manifestations can be divided into two main strands. In interventions that manifest creative identification with their author, as in the case of Bansky and Blu, it is difficult to think of their conservation due to the subversive and illegal character they present, but often these compositions have been accepted and actually incorporated into the urban landscape. The case of interventions commissioned on occasions of festivals or institutional projects is different, in which street art is used as an instrument of urban regeneration. In these cases, high market quotations can also be reached, with speculative reflections that have motivated tear-off interventions, as in Bansky’s graffiti in some cities of Germany and England. The question of conservation of street art continues to be controversial. It goes from the wall paintings removed between the protests of the inhabitants in Mexico and Peru, to the positive action taken by the institutions. One case is that of the oldest dated graffiti, La Madonna in Lipsia, cleaned up, repainted by the artist and protected by methacrylate. There are cases of replication, like a graffiti by Keith Haring of 1989, repainted on a new wall in Barcelona, while in Madrid it was proposed to subject to legal protection a Muelle wall painting of the Eighties. The conservation of murals is not an easy task: the question of the meaning of the operation and above all of the authenticity of the work remain fundamental. Furthermore, the reluctance of the artists in considering their work as artistic and the Kunstwollen himself who presides over each graffiti is to be taken into account. The answers to these questions are varied. The transfer of the paintings in museums is inappropriate, both for reasons of context, and because often operated against the will of the author, who rather seeks the perishable nature of the work. As a reaction to the musealization of one of his paintings, for example, Blu has deleted all his works in Bologna. The most important changes are perhaps by associations of researchers who, in various countries, try to preserve the work in their own context, according to the author’s intention.
