You can't stop abortion, but the issue of when the father wants the child and the mother doesn't does present a problem. Herbs have been used for thousands of years to auto abort a child. There's no way to stop it. I personally believe it is murder, but I'm not going to use force to stop the woman.
Nope, I do not believe in IP at all.
I'm not a "libertarian." I'm an individual liberty lover first, voluntaryist, and anarchist too. These issues could be worked out in the benefit of most people involved. Maybe the mother who wants to murder the child when the father doesn't would get rightly brought to court for her actions.