The line between libertarianism and anarchism can be a bit too fine at time for my tastes. Too many so-called libertarians are little more than disgruntled misanthropes who seem to think that their sociopathy is actually a political movement. Others strike me as children who have found religion and the words they read at lewrockwell dot com are gospel.
There are some aspects of libertarian ideology I do find attractive, though, as there are with conservative or liberal ideology, and I have met some libertarians who are very intelligent and mature, and who aren't in the least bit like the perpetually pissed or the childish. I have a friend who I respect greatly who is libertarian, so I refuse to paint all with the same brush.
In general, though, I find precious few libertarians who understand that no man is an Island. They go through life imagining themselves as rugged individualists even as they drive on roads built by society, use electricity provided for them by society, are protected by a military paid for by society and who blather away on an internet that would not exist were it not for the collaboration of countless people and institutions. It is the disconnect between how they imagine themselves and how they actually live that undermines the positions they take.