I was at OWS, and there had met a man who now is part of an anarcho-communist farm (which doesnt mean there are no rules or enforcement, but that the members all share in creating the rules, and holding equal standing with other members). This farm is within a half hour drive from New York City, where most of the collective members lived prior to the farm. They raise plants and meat to eat, trade, and sell as needed, and have other skills which they work share, and hire out when here is something they need which they cannot gain in the more broad context of capitalist society. The farm has been in opperation for multiple years now.
Furthermore, as regards Anarchists, there is no ban on using force ( see Spanish Civil War where Anarchists held Barcelona, or the Zapatista movement in Southern Mexico where there has been sucessful active militant resistance to the Mexican National military for almost two decades despite the best efforts of the Mexican government to murder anyone they think are "leading" the movement. There is quite the robust mechanism for widespread collective decision making in S. mexico as well)