Libertarians are not Socially Liberal, unless the term socially liberal means something different than the positions modern day Democrats take on social issues. Gun Right, affirmative action, and the fairness doctrine are an example of just a few issues where libertarians are at odds with social liberals on social issues. In addition, many libertarians are against abortion, as they see it as murder. Just because we are united in opposition to the extremely un-American Patriot Act, Military Commissions Act, etc. does not make us allies on social issues. For the most part, they have even stopped caring about these intrusions on our civil liberties since Barry-O got elected!
It depends on what sort of "liberal" one is talking about. For a social libertarian, liberal would mean "classical liberal," i.e. minimal government intervention in individual rights. In that sense, opposition to gun controls, affirmative action, and legislation which favors one group of individuals over another (even in the interest of "equality") would be a "liberal."
