Don't be taken in by these guys. "Anarcho-capitalism" would be a real mess. At a minimum one needs a tribunal to ajudicate disputes. If one is free to accept or reject the judgement the result would eventually be recourse to force on a large scale. When we look at societies given wholly over to private protection agencies in action, the picture isn't pretty.
Here is a brief critique of anarcho-capitalism that I googled. I can't vouch for the opinions expressed on the rest of the site, but it indicates some of the problems.
The frontpage of that website states that:
"The content of this website is primarily based on Ayn Rand's philosophy, Objectivism." It is really interesting that it provides such a cogent critique of one of the arguments most frequently put forth by some of the more stringent libertarians, given that she is the high Priestess and Prophet of that worldview.