Collage has been used by DIY enthusiasts since the 19th century (as an examination of many photo scrapbooks from the time will demonstrate). The technique entered 20th century art via Braque and Picasso, among others, and was soon taken up by Max Ernst, by the Dadaists, by Soviet Constructivists such as Alexander Rodchenko, and — for political purposes — by John Heartfield for anti-Hitler and anti-Nazi posters.
The Situationists proposed that such techniques could work most effectively to turn expressions of capitalist culture against itself, via subversive juxtapositions of imagery, and radical reinterpretation of accepted beliefs of traditional, or consumerist society. They called it détournement.
In the 1970s and continuing into the 1980s and today, collage, like stencils, became one of the primary DIY techniques used by musicians and others such as Malcolm McLaren and Jamie Reid in making posters, flyers, and illustrations both to advertise their appearances but also (as in the case of groups such as Crass), taking the lead of Heartfield and of the Situationists in using recognizable imagery to entirely different, and often subversive, purpose.