All libertarians are against the state, as such, be they left or right. Of course, for the last number of years right libertarianism has seemed like a good position to many people. They see quite clearly that the state is in the employ of the corporate and landed interest, and acts as the armed wing of that interest. I couldnt disagree with this in any way. The right libertarians put forward the idea that the only way for ordinary people to get ahead, is to take the weapon of the state away from the corporate interest and the big landowners, i.e. to reduce the size of the state, and give the ordinary people the ability to do their own thing. Again, this sounds like a very reasonable position to take. But, this is precisely where the theory breaks down. When the corporate and landed interest has already owned the state, and you reduce the state, all that happens is that the corporate and landed interest have carte blanche to run absolutely riot, and drive the people into the ground. This is what has happened over the last 20 years.
And nor, in reality, is the state reduced. The state has balooned in all western countries in the last 20 years. (Though I accept that most right libertarians would not go along with the psychotic behaviour of the neo-liberals - who really are an absolute plague on the world.) The state has been reduced in the matter of allowing ordinarly people to have democratic control over their environment - but it has vastly increased in the matter of creating reasons to pass the money of the ordinary people over to the oligarchy, and in the matter of burocratic control over the behaviour of ordinary people.
So, this is the root of the right libertarian error. Reducing the state, while the corporate monopolies and landowners still hold de facto power, is a pointless task from the point of view of liberty. You are just allowing the corporations to openly rule the world in their own interest, without any hope of democratic intervention. The problem is the oligarchy, not the state.