I have known my share of what Kevin Carson refers to as "vulgar libertarians" but whom I simply call "assholes" or "douchebags" as the case may be. They purport to value "individualism" so highly that any kind of cooperative or collaborative activity, other than what is done in the form of a business corporation, is anathema to them and decried as "collectivism". I confess that I am a collectivist. I have been known to play team sports, to sing in a choir, and to engage in activities with other human beings that involved cooperation and collaboration and adherence to group norms. I enjoy these things (not as much as some others since I am sometimes socially phobic), and I engage in them voluntarily. I value social responsibility, and I would like to think that this value guides my choices. If some individualistic asshole doesn't share these values, that's his privilege. He's still a socially irresponsible asshole, and I am under no obligation to approve of his socially irresponsible choices.
Let's take the inconsiderate bastard who drives a Hummer out of spite. I regard him as less virtuous than someone who drives a more fuel efficient vehicle, and I may use his choice of vehicle as a marker that indicates that he is an asshole whom I need not waste any time getting to know. That's my right. I have values, and I express them and act on them just like he does.
He also lacks virtue in that he is the kind of "libertarian" who turns other people off to the cause. Lots of people, when they think "libertarian", think about an asshole like the Hummer driving jerk. His social irresponsibility does a lot to set back the cause of freedom. He is worse than a statist, and he does for libertarianism what the Catholic League does for the Roman Catholic Church, that is to discredit it.
I recall an on-line discussion with some anarcho-capitalists who had written a piece about socially responsible investing and how it was irrational. I remarked that if one subjectively valued social responsibility, then such investments were perfectly rational. They conceded, oddly enough, that in their research they had not even considered the possibility that anybody would invest on any other basis than return on investment. I reckon it was a real mind bender for them. There seemed to be an unstated metaphysical assumption at work that the only proper basis for investing would be the raw return, that a purely individualistic calculus was the only proper way to decide anything. This is, however, a normative proposition in and of itself, an unexamined subjective preference that colors anarchocapitalist analyses. Douchebaggery and assholery are core virtues. They don't play well with others and reckon that nobody else should either.