Beyond the complicated etymology of the word transgression, some clues allow to analyse the meaning of transgressions in the media. The historical clue, to understand the unconventional role of the communication media on the social structures; the sociological clue, which puts in evidence the processes of materialization of the contemporary media born in the nineteenth-century metropolis; the social-anthropological clue, which catches forms of transgression from the daily life in addition to the role of the historical avant-gardes; the social-semiotic and social-linguistic clues, where structuralism and narratology put in evidence the generative ability of transgression. Up to the political clue. These are the bases to bring to mind the structural aspect of transgression, and to ponder over the meaning of those unconventional procedures that fed from the bottom, by subjects, instincts and languages that the official cultures tend to restrain are able to change the world.