In this first decade of the twenty-first century we are caught up in the midst of a technological shift of the kind that Walter Benjamin, in his 1936 essay ‘The Work of Art in the Age of Mechanical Reproduction’, attributed to the increasing popularity of photography in the early twentieth century. The essence of that change was the unprecedented capacity to create infinitely reproducible multiple copies. For the first time the idea of the primacy of the singular work of art was seriously open to question. ‘The history of every art form,’ writes Benjamin, ‘shows critical epochs in which a certain art form aspires to effects which could be fully obtained only with a changed technical standard, that is to say, a new art form’. Photography initiated a change that Benjamin recognised as being as profound in its impact on people’s lives as the introduction of the printing press.