Dumpster diving for food has apparently become a whole ideology now, Freeganism:...

Dumpster diving for food has apparently become a whole ideology now, Freeganism: http://en.wikipedia.org/wiki/Freeganism

In their own words: "[Freegans] embrace community, generosity, social concern, freedom, cooperation, and sharing in opposition to a society based on materialism, moral apathy, competition, conformity, and greed."