Ideology is defined as a systematic way of thinking that is self reinforcing and closed circuit.
Systematic means simply that one concept progresses logically to another.
Closed circuit means that the system is not receptive to new ideas or facts that may be contrary to the system.
A systematic thought process that is open circuit and incorporates new events is called a philosophy.
Pay attention now...
Here's the gist of this post...
Libertarian ideology is such that it rests upon a principle assumption; The more power government has, the less power an individual does.
So, based on this principle, many Libertarians advocate for privatization of services currently rendered by the government.
Now, let's logically follow what actually should come next. Government in a democratically representative republic such as the United States, is the represented will of the people (and corporations thanks to the various suspect Court decisions). Therefore, the government has a direct incentive to do the People's will because if they act contrary, then they lose power to make those sorts of decisions. Take a look at the recall efforts in Wisconsin for the repercussions of fucking with The People.
Now, in privatization, you are taking services previously rendered by the government (such as roads, security, civil courts, social safety nets like Social Security and Medicaid, etc.) and placing those services in the hands of private entities. Those entities now have a monopoly on those services, but without a check or balance. The Libertarian rejoinder to this is that the "Market" will serve as a check rather than regular elections.
This assumption, is of course, fucked up. Once a monopoly is established, it takes a power greater than the monopoly to break it up. Markets by their very nature calcify into large wealth pools. If you want historical examples, I suggest reading up on The Gilded Age and The British East Tea Company.
The Libertarian ideology pushes policies that leads to authoritarianism. How so? Because without a check or balance on the monopoly (as we do with representative government), the societal wealth and resources are now in the hands of few people who are protected by those very resources.
Check it.