I am an Anti-Capitalist! Yes, it is true. Perhaps you thought that libertarians or anarcho-capitalists (!) must be pro-capitalism. This is not true; I am very much opposed to capitalism. Just like all other anarchists I sincerely do not appreciate certain capitalist structures — economical or social. Capitalism is oppressive and exploitative.
On the other hand, I consider capitalism the liberator and spontaneous structure of true anarchy. It is simply a matter of which definition I choose to use. This is the problem of dogmas being expressed using certain terms: One has to see the concept behind the term not to get confused. In other words, a term may not mean the same thing for different people: Being an anarchist I am opposed to capitalism in the Marxist sense, but as a libertarian I am very much pro-capitalism — in the Austrian sense.
The global anti-capitalist movement includes thousands if not millions of people being sick and tired of capitalist exploitation. Many of these people are simply dorks and dumb-asses following a "cool" trend or a leader. But many of them are rather intelligent beings protesting a real plague of modern times. The former are opposed to anything involving money, since they believe money, the market, companies and profit being parts of a global conspiracy calling for the exploitation of all non-bourgeoisies (i.e. workers). I despise these people, and would not have anything to do with them.
The other group consists of people wishing to end the unfair elements of the economy, what they call capitalism (i.e., what you and I would call state capitalism). This includes state regulation of markets, subsidies of companies and certain industries, laws restricting contracts of trade and employment, etc. For a socialist it is most unfair that the state through such measures makes the market for work and workers unfair: Salaries are forcefully held down and there is no real freedom of employment.
Even though industrialists and "capitalists" are taxed, many corporations manage to avoid the better part of such taxes, while they through donations and lobbying can buy monopolies and other advantages to competitors, tax-payer financed infrastructure etc from power-hungry politicians. This is the greater part of the unfairness and exploitation Marx identified as "capitalism." In this sense, I am most certainly an anti-capitalist.
Capitalism in the Austrian sense, i.e. the definition regularly used by libertarians like you and me, includes nothing of this sort. Here, capitalism is simply the voluntary agreement between free individuals to exchange products or services; and to hold the unrestricted right to what we produce: Our property. Anarchists and "libertarian socialists" are usually not opposed to this. This is simply freedom, anarchy! Unless one insists on using the term capitalism. They have a hard time seeing through our definition of capitalism (they're using the term in its original meaning) just as we can never see socialism (in the individualist anarchist sense) for what it really is: A focus in discussions and debates on the working population and the rights of the common man against the state. Tell me, what is wrong with such socialism?
So I am a capitalism-loving anti-capitalism anarchist. There is nothing strange about it; I simply choose to use the term in both definitions.