When you think about it, true anarchy is not the absence of government.
As we usually conceive it, anarchy is the absence of law. When there is no law, the weakest suffer. Those who are stronger rule over those who are weaker. Only respect for the law, a law which applies equally to all people, can prevent the powerful from taking advantage of their position.
A government unconstrained by the rule of law is thus the very definition of anarchy--that is to say, might makes right. The real anarchists are those who wish us to yield more and more power to the state.