David Friedman sees Amish communities as "evidence of at least one form of (very structured) anarchy that works":
It is a very strange form, since the rules that the Amish are under are considerably more constraining—including rules on what styles of clothing they can wear, rules against owning automobiles or flying on airplanes, and much else—than the rules the rest of us are under. But those rules are all voluntarily accepted, and the system that generates them may reasonably be viewed as a competitive system of private law. … It's true, of course, that the Amish are under the rule of the U.S. (or, for a smaller number, Canadian) government. But they receive very few services from government, since they are unwilling to accept most of the conventional forms of government aid and, as pacifists, are unwilling to report crimes against themselves to the police or sue in the government courts to collect debts. Off hand, the only significant benefit I can think of that they get is protection against foreign invasion.