Have you noticed how so many Christians love to tell each other how to live? Don't drink, gamble, shop on Sunday, listen to secular music, or else declarations on what you should or shouldn't eat, how often to fast or go to church, or whatever, the list can (depending on the particular Christian circles you mix in) be pretty endless. Meanwhile, despite claims to the contrary such a prescriptive mindset is all too often a means of determining someone's spirituality. In short, it degenerates into a form of judgementalism.
Lest some non-Christians feel somewhat smug at this stage, neither is this feature unique to Christianity. Whether telling you what is politically correct or not, that you must accept every form of behaviour as equally valid or (paradoxically) that some lifestyle choices are wrong, making you feel guilty about your eco-choices, or whatever, just as with judgemental Christians being told what to do or not seems nearly always to be couched in moral language: "If you do this, then you are moral/ethical (Christian equivalent: spiritual), but if you don't do this then your not". In short, it's human nature to tell people what to do.
However, there are those in the secular realm who are true libertarians. What individuals do, they say, is no one else's business, and neither other individuals, institutions, wider society, or the State have any right whatsoever to legislate against their personal choices. I must admit to a certain sentimentality towards such a view. Within a Christian context, what I do no one else's business. My relationship with God is exactly that - something between me and God - and as a (I hope) mature Christian I know exactly when I'm displeasing Him. Thus, it is up to me - it is my responsibility - to ensure everything I do and how I live is right and moral and biblically acceptable. This, in fact, is the whole basis of Paul's famous liberty of conscience passage in Romans 14.
The problem is, where do we draw the line? Choosing to live righteously or sinfully is all well and good, but we simply cannot do whatever we want, whether in the secular or Christian realms. And here, in fact, is where may draw a parallel between both spheres to determine the line which should not be crossed. In Romans 14 the apostle Paul makes clear that despite his freedom to live as he pleases in light of his relationship with God, he would not do anything at all which causes another brother in Christ to stumble. In short, what we do is between us and God, and no one else has the right to judge us. (I certainly don't want to judge anyone else's actions - I have enough judging and worrying to deal with my own life and how that might displease God). But when our public actions might have a detrimental effect on the faith of a brother or sister in Christ, then it becomes problematic. Thus Paul says we need to take care how we flaunt our liberty (providing it is not sinful), otherwise we become answerable to God and the wider Christian community.
And in the name consistency, surely this is how it should be with secular libertarianism. As a Christian, I may find all manner of behaviour within society deeply distasteful, even disagreeing with it profoundly. But ultimately, the actions of such individuals are between them and their conscience (and ultimately, of course, between them and God). Yet just as with Christianity, libertarians have no right to cross a particular line, namely, how certain actions will have a bearing on others around them. And here's the rub, isn't it? Whether exploitation, abortion, adultery, or whatever, too many actions carried out in the name libertarianism all too often cause misery and anguish for others. Whether Christian or secular, then, it's no one else's business what we do... until it causes misery and pain for others.