A libertarian world really is a nightmare for the people who believe that the government world does not essentially do exactly the same thing, but with better PR, and maybe different price points. The government version of freshman physics assumes a spherical cow. The libertarian version assumes a spherical pig. The Internet argues about the flavor of the milk.
The truth is that no one will admit there may be warts on their favorite goblin baby until they are growing one right on the end of their pointy little green nose. I have already spent an awful lot of time on the Internet arguing both for and against libertarian ideas. The only good thing that can really be said about the adherents of alternate political views is that at least they recognize that change is only possible if you try something different. You can't really ever predict the outcome of a system when you divorce its ideal workings from the real people who will eventually be running it.
Part of me wants to be a libertarian/anarchist, but the way their ideas resemble freshman physics explanations that ignore friction and wind resistance really turns me off.