I followed up on that link and found it extremely interesting and thorough.

But my first impression was that it was meant as a very sophisticated job to take the animal rights movement apart from the inside by using their own argument to drive it to its logical absurd conclusion. The longer I read the more I realized that it was meant dead serious. Someone really means to apply empathy (which after all is an evolved trait) to its utmost extreme. Kind of like an AI that had no other values would.

I posted something like this as a risk of Unfriendly Natural Intelligence earlier but wouldn't have guessed at how far it really can be taken.

There are a few sentences where one could think that he should see the outside view:

we should also remember that many other humans value wilderness, and it’s good to avoid making enemies or tarnishing the suffering-reduction cause by pitting it too strongly opposed to other things people care about.

evolutionary pressure pushes prey species to avoid drawing attention to their suffering and to pretend as though nothing is wrong

But it doesn't hit home. I can almost hear him answering the question "but you evolved to feel empathy too" with the UFAIs answer "yes I know, but nontheless the suffering must be reduced." (and an actual suffering reducing UFAIs would probably go on to eradicate all life as that minimizes suffering because lower life forms have net negative lifes and dominate the sum so killing them is necessary - that the humans have to go too because of lack of food etc. is only a minor term).