For any society larger than Dumbar's Number (http://en.wikipedia.org/wiki/Dunbar%27s_number) that is dependent upon members of that society treating each other with the kind of mutual respect that is required for a truly voluntary commune to exist, some form of social hiearchy with the capacity to impose it's will upon individuals is required. Otherwise it's unstable. This pretty much describes any group larger than a (relatively small) church business meeting. No town, city, county, state or nation can function otherwise; regardless of whether or not they are communist, libertarian or other. Even libertarian ideals require a common social order that can be enforced upon individual members; but ideally that common social order is minimalist in nature. Communism cannot be minimalist in this fashion. It's literally impossible.