I am of the thought that Anarcho-capitalism is a contradiction onto itself. One cannot possibly claim to be an anarchist while supporting the extreme forms of tyrannies that capitalism entails.
Capitalism was, and still is, deeply involved with corrupt government (as if there is any other kind...). Anarcho-capitalists recognise the deeply corrupting nature of that association, and assign many of the historic failings of capitalism to that association.
By freeing itself from government, however, capitalism in its pure, non-governmental (and thus, semantically, "anarchic") form would be associated with unprecedented human progress, innovation and flourishing, not "tyranny".
Conversely, many of the ideas of left-anarchists involve the creation of manifest tyrannies. In a typical scenario, an individual as completely at the mercy of his co-workers, co-consumers and neighbours. Since collectives are invariably captured by popular demagogues, vote brokers and the socially-influential, tyranny is all-but-guaranteed whenever individuals are so comprehensively-restricted to acting in conformity with established groups.
Free men are not equal and equal men are not free.
Government is not the solution. Government is the problem.