For a second, in the right light, it looks as if Megan McArdle may have achieved self-awareness:
This is a question I’ve asked myself before, funnily enough, when arguing with anarcho-capitalists. For those who do not follow the ins and outs of libertarian sectarianism, anarcho-capitalists want to replace the state with private institutions, with insurance companies and private security forces substituting for most current government functions. But when I’ve probed into the actual mechanics of this, I’ve often found that anarcho-capitalists end up describing something unpleasantly like a police state, only not called “the government” -- like giving insurance companies and private police forces the ability to perform warrantless at-will searches in order to prosecute crimes. One way or another, society is going to protect itself against theft and violence, rape and murder, and putting those tools in the hands of private parties causes much the same trouble as they do in the hands of the police.
Alas, no. The problem is, when the state oversteps its role, there is at least a formal mechanism for addressing that problem -- you can throw the bums out. (Yeah, I know it's not a perfect recourse, but if it were useless why would all those people spend so much time and money trying to achieve electoral results at all?) Once this social contract is swapped out for something more like Facebook's terms of service, however, you get only what you can negotiate -- and with collective bargaining being swept away, you can't negotiate shit.
So when McArdle says, "there may be trade-offs: The price of safely enjoying our vices may be surrendering some of our civil liberties, either to the government or to private parties," it doesn't mean she's had an epiphany; it just means she's gotten smart enough to do false equivalence with a straight face.