That's not really my basic bitch against the libertarians though. My real complaint is the same as my complaint against most religion - its premise is a fraud. For those who can't stand to wait for the punchline, I believe that trying to implement libertarian principles leads to tyranny or social disintegration. Demonstrating that takes some historical (and pre-historical) context.
For all but the last 15,000 or so of the 100,000 years the human species has existed, all humans lived in a sort of libertarian paradise - no government, no organized religion, and few social constraints on behavior. A few lived that way until very recently. In many places people were able to achieve a kind of equilibrium with their environment, with population naturally controlled through homicide, infanticide, and starvation.
Clearly, humans are well adapted to that kind of life, so its no wonder libertarians would like to recapture that. The catch - there's always a catch - is that they don't want to give up the comforts of civilization.
Hobbes and Jefferson had somewhat different ideas about the proper role of government in civilization, but I think we now have some historical perspective on actual as opposed to theoretical development, so that will be my approach. The serpent in the above described libertarian paradise appeared in the form of horticulture and the settled life it required. Hunter gatherers have no property but that which they can carry with them, so their wives and daughters are almost the only things they have worth stealing. Farmers have property - stored food, dwellings, and tools too big to lug around much. They also develop population densities large enough to become a menace to their hunter gatherer neighbors and each other. Thus, the necessity for organized defence.
It's doubtless natural to be willing to fight in defense of one family and property, but it's decidely unatural to lay one's life on the line for the neighbors. Consequently, tribal and larger societies develop an array of strategies to compel service in the common defense, including elaborate patriotic social structures, organized religion, professional armies, and, or course, the naked threat of violence against non-participants. Military organizations inevitably partially enslave their members.
I'm pretty sure libertarians oppose slavery in principle, but how can you have armies without it. The only good defence anyone has found so far is the republican form of government. Unfortunately, as the history of Greece, Rome, Florence and many others shows, the Republic is fragile. There are a number of diseases that afflict the Republic, as Adams and others among the founding fathers noted. One of the most pernicious is the concentration of wealth and power in a few dynastic families. Libertarians, at least our current Rand influenced version, seem unwilling to address this problem. Several times our ancestors found it necessary to attack this problem, by eliminating primogeniture, instituting the income tax, and inheritance and gift taxes.
As long as libertarians refuse to embrace this necessity, they are the enemies of freedom, and need to be treated as such.