I'm pretty uncomfortable with the entire idea of sperm donations, actually. Voted no.
Interesting, I don't think I've heard an argument against them before. Why?
Really? It's the same arguments that are used against IVF in general, which are pretty common.
1) Why go to so much trouble to create a new life when there are already so many orphans in the world? It's basically just because people are vain, they can only love a child if it has their genes. Such people shouldn't be parents in the first place.
A significant of transnational adoption are stolen and/or bought children even in the third world, where we would think there was a oversupply. So to some degree those "unwanted" children are just one more way, for the rich world to extract resources, this time the most precious one they have at allm from the poor world.