Urban living involves a daily onslaught of advertisements, corporate art, and mass-mediated popular culture. As oppressive and alienating as this spectacle may be, its very ubiquity offers plentiful opportunities for semiotic jiu-jitsu and creative disruption. Subversive and marginalized ideas can spread contagiously by reappropriating artifacts drawn from popular media and injecting them with radical connotations.
This technique is known as détournement. Popularized by Guy Debord and the Situationists, the term is borrowed from French and roughly translates to "overturning" or "derailment." Détournement appropriates and alters an existing media artifact, one that the intended audience is already familiar with, in order to give it a new, subversive meaning.