When I point out that banning aborion doesn't give the unborn more rights than the born, they say [crap] like "give me your kidneys then". They seem to be under the impression that fetuses just walk around the streets looking for women to "glom onto", and that having an abortion is just refusing permission.
But I hope anyone arguing on the internet knows where babies come from, so I'll spare you another Post 239.
The offspring in no way chooses his position; it is forced upon him by the mother. And abortion occurs after implantation, and is performed by actively killing the prenate, not merely "unplugging". To have an abortion is therefore analogous to bringing someone onto a cruise in their sleep and dropping them in the middle of the ocean. After all, who are we to force you to carry him on your ship to Bermuda.
But I guess this is all irrelevant since granting the unborn their human rights and insisting women take responsibility for your actions is just a punishment for sexuality.
For more, see Libertarians for Life's article "Abortion and Thomson's Violinist: Unplugging a Bad Analogy, Comments on why the prenatal child has the right under individual liberty to be in the mother's womb".