One form of guerrilla communication is the creation of ritual via participative public spectacle to disrupt or protest some public event or to shift the perspectives of passers-by. Such spectacles often take the form of street and guerrilla theater, such as the theater of Augusto Boal. Another way to create such spectacle is via tactical frivolity.
Pie-throwing as performance art is a classic form of guerrilla communication. The event is a moment turned inside-out; art is made from the reactions of the bystanders, turning spectacle to ritual. Other forms of guerrilla communication include adbusting, graffiti art, hacktivism (notably cyber squatting), and reclaiming.
See also: KLF, Reclaim the Streets, Culture jamming, spass guerilla, subvertising, sniggle, the Publixtheatre Caravan.