Let’s face it, there are a lot of jackasses who call themselves libertarians. If you get some of them talking long enough they might eventually say something like “it’s ok to stockpile nuclear weapons in your basement – everybody has a right to defend themselves”, “It’s ok to use crank just as long as you don’t hurt anybody”.
Even if you left everything up to individuals and the private sector you will end up with entities that look no different from our current federal gov’t and lots of corporate america. If some bad ass guy with lots of weapons enters our anarchic utopia and starts stealing, raping, murdering, etc, eventually the others will coerce and defend themselves. These individuals might decide to keep the coercion intact and have some form of Gov’t.
