Freegans are trying to cut themselves off from the consumer economy, at least, that's what freegan.info says. But when you get right down to it, documents like http://freegan.info/?page=WhyFreegan
suggest that their modus operandi is a lot less, ahem, moral than I would prefer to be, and a lot more like the freeloading variety of hip upper middle class anarchist.
As someone pointed out, eating out of dumpsters because you don't *want* to work may end up vicimizing people who *can't* work: http://www.tigersandstrawberries.com/2006/02/09/freeganism-whats-up-with-that/