libertarians, as much as I like them, are far more interested in the academics and theoretical side of liberty rather than it's practical application.
unfortunately there is such a thing as things that are too dangerous for society without certain regulation. that's what government is FOR.
(right now the pure libertarians are pointing, mouth agape, yelling at their computer monitors "STATIST!!!!!!!!")
for example, I'm all for regulating antibiotics.
a pure libertarian would allow anyone to get any antibiotics they want, at any time. the known result of that policy is drug-resistant forms of disease that eventually will kill a lot of people. we've already seen this in the drug-resistant forms of TB and staph that have been coming from countries that don't regulate.
theory is great...but theory doesn't always work once it's removed from the vacuum of academia.
in theory, a democracy works great. everyone votes on everything. but the founders knew that a democracy degenerates into mob rule pretty quickly. thus, we arrive at a republic. the founders split the difference between academic theory and human nature and gave us an imperfect, but free, government. and a lot of our freedom actually extends from those imperfections...things don't work well or quickly. it's hard to get steamrollered by a government that can't pick up speed.
once again, theory is great. but once placed in the world it doesn't always work.