Culture jamming, coined in 1984,denotes a tactic used by many consumer social movements to disrupt or subvert mainstream cultural institutions, including corporate advertising. Culture jamming is often seen as a form of subvertising. Many culture jams are intended to expose apparently questionable political assumptions behind commercial culture. Common tactics include re-figuring logos, fashion statements, and product images as a means to challenge the idea of "what's cool" along with assumptions about the personal freedoms of consumption.
Culture jamming sometimes entails transforming mass media to produce ironic or satirical commentary about itself, using the original medium's communication method. Culture jamming is usually employed in opposition to a perceived appropriation of public space, or as a reaction against social conformity. Prominent examples of culture jamming include the adulteration of billboard advertising by the BLF and Ron English and the street parties and protests organised by Reclaim the Streets. While most culture jamming focuses on subverting or critiquing political or advertising messages, some practitioners focus on a more positive, musically inspired form of jamming that brings together artists, scholars and activists to create new forms of cultural production that transcend rather than merely criticize or negate the status quo.
LINK: http://en.wikipedia.org/wiki/Culture_jamming
This video on Google Videos also help be understand the ideas behind culture jamming:
LINK: http://video.google.com/videoplay?docid=-1777885894535257561#
Culture jamming to me is a form of vidding as discussed this week except they are using video and music to use pre-existing corporate identities and the connotation that goes with them to produce a disruptive, sometimes shocking, message which makes the viewer reassess their thoughts on a particular person, corporation or issue. These vidders are I think "anti-fans" in that they usually wish to highlight the problems with something rather than the positives of something. And do so for different moral, ethical, political reasons.