Anarchism is probably the worst threat to capitalists, and they have spared no effort in trying to distort its ideas and crush it in order to keep its ideas and history from the minds of working people. Although I've read a lot of literature on the left, I am no expert on anarchism. However, this article appears to provide excellent insights on contemporary and historical examples of anarchist thought and actions.
Anarchists believe that men should not rule or be ruled but form voluntary cooperative relationships to accomplish what they cannot do for themselves, bottom up democracy. Membership in any collective is voluntary and fluid. The three corruptions of power as far as Anarchists are concerned are the power of the state, the power of the church, and the power of capital. They refuse to recognize the authority of all three.To learn more about the Anonymous group he refers to in his article, check this and this out.