Most libertarians have varying stances that all develop from the non-aggression principle ("in a free society, you have the freedom to do whatever you want so long as it does not infringe on the rights of anybody else.") I have never heard a compelling argument against the NAP, because it can be interpreted so broadly. Even some of the pro-no-asking-questions people on this thread are using the NAP, if unwittingly, to justify their positions.