People like this are a burden on society. He most likely has an attitude of "I don't give a shit. I don't need to take care of them. Society will do it"

I say sterilization is in order.

Very interesting food for thought. I'll actually have to ponder that for a minute.

Speaking as a self proclaimed libertarian I have to disagree with your assessment of their view on this subject. I am neither shocked nor appalled. While the male is not physically stuck with the kid after the deed I strongly believe that by having a kid you have a responsibility to make sure that kid does not drain the resources of society at large. If you are unable or unwilling to provide for the child (thus leaving the burden to society) society has the right to force you to provide or in this particular case where it is apparently impossible to force you to provide, has the right to prevent you from creating further burdens on society.

Libertarianism does strongly support the right of people to sustain themselves outside of social constructs, but if a person fails to fulfill the obligations they create, I don't think there is anything inherent in libertarian thinking that prevents society from attempting to collect all of, part of or at least limit the size of that debt. 

Libertarianism would necessarily oppose a limit of the number of children on a person who has the means to support them. But I think an expectation that a person limits the burden they puts on society as a whole, and steps to reduce the burdens that society must pay for is a central tenant to libertarian political philosophy. 

Beyond,

The man gave his sperm, NOT a child. Because the woman owns her own body, she can take this gift from him and do as she desires - namely have a child. It is not his responsibility. (Locke, on self ownership)

Perhaps it can be said that for stable couples that it is a shared choice by two individuals that they wish to make another individual, in which case I would agree that the father would share a responsibility for the child, but that is obviously not the case in this instance - The mother must take on the responsibility (in a libertarian context), knowing the proclivities of the father.

Locke expressly refutes any such ownership, however, and it's a strong and fundamental tenant of Libertarianism that humans are not owned (at least not without their expressed request to be). Nozick offers some ideas for a rebuttal of this 'ownership of children' by parents:

"(1) Something intrinsic to persons bars those who make them from owning them ...(2) some condition within the theory of how property rights arise in productive processes excludes the process whereby parents make their children as yielding owner- ship, or (3) something about parents bars them from standing in the, or a particular, ownership relation, or (4) parents do not, r d y , make their children. (Nozick, 289)"

However, as Nozick himself proposes that individuals have the right to sell themselves into slavery (see our other thread on this!), then people can be considered property in certain circumstances, thus refuting 1. (I won't go into this in greater detail for now - there's another thread where Beyond and I are discussing the validity of self-imposed slavery).

Now Locke's views are interesting because his viewpoint stems from a belief that all humans are owned by God, and therefore do not have the right to take ownership of something already owned by God. However, as atheists we must reject that premise, so something further is required to differentiate humans from property. Here, the view of libertarians in general come to the rescue - A libertarian does not need to justify the choices they make to anyone except themselves, and so are perfectly within their rights to claim as axiomatic that people are different from property, then create a moral compass based upon this.

The outcome this leads to is: Either children can be considered property, or they must be treated as autonomous individuals. If the former, then in this case they are the property of the mother. If the latter, then they are responsible for themselves; no-one else need bear that responsibility.

Therefore, my original paragraph on the libertarian viewpoint is, I believe, still valid, Though I take your point on societal debt.

EDITED for a few typos

GodsUse, good points and I think that two intelligent libertarian phillosophers could certainly disagree on the issue and argue among themselves using core libertarian principles. Libertarian philosophy is rather light when it comes to the issue of humans who are incapable of being autonomous such as children and the mentally ill.

Rothbard wrote an interesting essay, "Kid Lib" on the subject attempting to reconcile libertarian philosophy with what most people would see as the necessity of controlling children available here. (essay starts on page 145). Ultimately, I think he failed as he switches his view of children within the same essay. At one point he compares the child to a "house guest" that must follow the rules laid out by the owner of the property (the parent(s)), yet at other points he treats children as property. He attempts to solve the dichotomy by protecting the right of the child to run away. 

I think that viewing the relationship as a trustee is a useful analogy since it acknowledges the power to make decisions but also an obligation (moral and legal) to do what is in the best interest of the beneficiary (in this case the child). The problem with a child having a right to run away is the maturity of the child. If a six year old attempts to run away I think pretty much everyone would agree that a parent must use some level of coercion to bring the child back because a six year old is incapable of caring for themselves. If a 16 year old runs away, I would say that in most cases they are mentally mature enough to make that decision and society should protect their freedom to make that decision. The problem is that humans don't all mature at the same speed so each case has to be considered on an individual basis with no perfect test- meaning that injustices will occur. 

But back to your original point, let us consider that children are the beneficiaries and the parents are the trustee. Now are both parents automatically co-trustees? Or just the mother because of the biological reality that she is physically attached to the child until birth? I would argue that it is clearly both unless some formal agreement is made between the parents. The child, by definition, could not consent to its own creation. He or she will be born into this world naked, defenseless and unable to provide daily necessities of life. The fathers obligation is not to the mother, it is to the child and to the society that his creation will be set loose in until such point that the child is capable of acting as an autonomous member of society.

By creating the child without the child's consent, the father by default becomes a co-trustee in ensuring the child is provided for. Anything less is causing harm to the child through negligence. For example, suppose I became a trustee for my parents estate because they were for some horrible reason unable to manage their finances. As a practical matter my sister also becomes a co-trustee because she lives closer to them. Then I decide to shirk my responsibilities as a trustee and completely ignore everything. My sister, either through incompetence or malice drains my parents estate for her own pleasure and makes financial decisions that are directly contrary to their interests. Am I liable? I wasn't the one making decisions, but yes, I am legally and morally liable through my negligence.

If a father creates a child and fails to provide for and protect that child through negligence, he is definitely morally liable, and I believe should be legally as well. The idea that a father can simply walk away because the mother decided to accept his "gift" of sperm and that somehow nullifies the fathers obligation to the child doesn't hold up. I can't become a co-trustee and then simply decide to ignore my responsibilities and when you create a child you are essentially agreeing to become their trustee. To ignore that responsibility causes harm to the child.

But like I said, you are probably right that some libertarians might disagree with my comparison and make principled arguments against it. Issues of non-autonomous people is an area that I think the big names in libertarian philosophy have failed to flesh out thoroughly, probably because it is a lot more murky and a lot more prone to situations that seem to require exceptions. Philosophers, as idealists, never like exceptions. I consider myself a more practical libertarian and when philosophy clashes with reality I am prepared to make exceptions to have a preferable result.