In the book New Media Art, Mark Tribe and Reena Jana named several themes that contemporary new media art addresses, including computer art, collaboration, identity, appropriation, open sourcing, telepresence, surveillance, corporate parody, as well as intervention and hacktivism.[8] In the book Postdigitale,[9] Maurizio Bolognini suggested that new media artists have one common denominator, which is a self-referential relationship with the new technologies, the result of finding oneself inside an epoch-making transformation determined by technological development. Nevertheless, new media art does not appear as a set of homogeneous practices, but as a complex field converging around three main elements: 1) the art system, 2) scientific and industrial research, and 3) political-cultural media activism.[10] There are significant differences between scientist-artists, activist-artists and technological artists closer to the art system, who not only have different training and technocultures, but have different artistic production.[11] This should be taken into account in examining the several themes addressed by new media art.