Kim Stanley Robinson quote: “That's libertarians for you — anarchists who want police protection from their slaves.”

“Even if you want no state, or a minimal state, then you still have to argue it point by point. Especially since most minimalists want to keep exactly the economic and police system that keeps them privileged. That’s libertarians for you—anarchists who want police protection from their slaves.”

Kim Stanley Robinson book Green Mars

Source: Green Mars (1993), Chapter 7, “What Is to Be Done?” (p. 370)

“A libertarian is someone who can believe that the police are no more than a gang of thugs without realizing that in the absence of police, thugs will gather into gangs.”

S.M. Stirling (1953) Canadian-American author, primarily of speculative fiction

Usenet group rec.arts.sf.written (7 July 2000) http://groups.google.com/group/rec.arts.sf.written/msg/19970c9f41512518

“As for libertarian, I've been one all my life, a radical one. You might use the term "philosophical anarchist" or "autarchist" about me, but "libertarian" is easier to define and fits well enough.”

Robert A. Heinlein (1907–1988) American science fiction author

1975 Statement to Judith Merrill, who had called herself a democrat and a libertarian, stating that such terms described him as well, as quoted in Robert A. Heinlein : In Dialogue with His Century, Volume 2: The Man Who Learned Better | 1948-1988 (2014), p. 389
Context: I think that describes me, too — still a democrat not because I love the Common Peepul and not because I think democracy is so successful (look around you) but, because in a lifetime of thinking about it and learning all that I could, I haven't found any other political organization that worked as well.
As for libertarian, I've been one all my life, a radical one. You might use the term "philosophical anarchist" or "autarchist" about me, but "libertarian" is easier to define and fits well enough.

“My early work is politically anarchist fiction, in that I was an anarchist for a long period of time. I'm not an anarchist any longer, because I've concluded that anarchism is an impractical ideal. Nowadays, I regard myself as a libertarian.”

Robert Anton Wilson (1932–2007) American author and polymath

"Robert Anton Wilson: Searching For Cosmic Intelligence" - interview by Jeffrey Elliot (1980)
Context: My early work is politically anarchist fiction, in that I was an anarchist for a long period of time. I'm not an anarchist any longer, because I've concluded that anarchism is an impractical ideal. Nowadays, I regard myself as a libertarian. I suppose an anarchist would say, paraphrasing what Marx said about agnostics being "frightened atheists," that libertarians are simply frightened anarchists. Having just stated the case for the opposition, I will go along and agree with them: yes, I am frightened. I'm a libertarian because I don't trust the people as much as anarchists do. I want to see government limited as much as possible; I would like to see it reduced back to where it was in Jefferson's time, or even smaller. But I would not like to see it abolished. I think the average American, if left totally free, would act exactly like Idi Amin. I don't trust the people any more than I trust the government.

“By going on the defensive… libertarians are, inadvertently, conceding that speech should be policed for propriety, and that those who violate standards set by the PC set are somehow defective on those grounds alone and deserve to be purged from “polite” company.”

Ilana Mercer South African writer

"Fee-fi-fo-fem, I Smell The Blood Of A Racist", http://www.wnd.com/2014/05/fee-fi-fo-fem-i-smell-the-blood-of-a-racist/ WorldNetDaily.com, May 15, 2014.
2010s, 2014

“Well I sometimes call myself a libertarian but that's only because most people don't know what anarchist means. Most people hear you're an anarchist and they think you're getting ready to throw a bomb at a building.”

Robert Anton Wilson (1932–2007) American author and polymath

Interview in TSOG (2002) http://www.blackcrayon.com/ (sound file) http://www.blackcrayon.com/audio/RAW-anarchism.mp3
Context: Well I sometimes call myself a libertarian but that's only because most people don't know what anarchist means. Most people hear you're an anarchist and they think you're getting ready to throw a bomb at a building. They don't understand the concept of voluntary association, the whole concept of replacing force with voluntary cooperation or contractual arrangements and so on. So libertarian is a clearer word that doesn't arouse any immediate anxiety upon the listener. And then again, libertarians, if they were totally consistent with their principles would be anarchists. They take the position which they call minarchy, which is the smallest possible government... The reason I don't believe in the smallest possible government is because we started out with that and it only took us 200 years to arrive at the czarist occupation of government that we have now. I think any government is dangerous no matter how small you make it. Instead of governments we should have contractual associations that you can opt out of if you don't like the way the association is going. Religions fought for hundreds of years over which one should dominate Europe and then they finally gave up and made a truce, and they all agreed to tolerate each other — at least in this part of the world... But I think government should be treated like religion, everyone should be able to pick the kind they like. Only it should be contractual not obligatory. I wouldn't mind paying tax money to a local association to maintain a police force, as long as we need one. But I hate like hell paying taxes to help the US government build more nuclear missiles to blow up more people I don't even know and don't think I'd hate them if I did know them. A lot of anarchists had a major roll in influencing my political thinking, especially the individualist anarchists. Benjamin Tucker and Lysander Spooner especially. But I've also been influenced by Leo Tolstoy's anarcho-pacifism. And I find a lot of Kropotkin compatible even though he was a communist anarchist. Nothing wrong with communist anarchism as long as it remains voluntary. Any one that wants to go make a commune, go ahead, do it. I got nothing against it. As long as there's room to the individualist to do his or her own thing.