Is the rabbit happy when it spends it's life terrified that it is going to be caught and eaten by a fox or bobcat or large owl? Is the fox happy when it is on the edge of starvation?

I've been keeping a couple goldfish for the last couple years (basically the only pet we can have in our apartment without having to pay a monthly fee). As such I've read a bit about those who keep and raise fish.

There are some species of fish that would be extinct if it wasn't for the pet trade. Their natural habitats are gone or can no longer sustain them. Even those that aren't endangered live far less dangerous lives in an aquarium, where the only danger is lack of care from the owner, or poor care. The most common problem is over-feeding. Fish are cold-blooded, their dietary needs are vastly different than warm-blooded animals. They can literally go weeks without eating with no harmful effects. Many fish you see are fat, they'll eat as much as you give them (in the wild food is scarce, they have to eat when they can!) and as a result many die prematurely in captivity from problems such as liver disease caused by excessive fat.

The point is that the whole anti-pet animal rights environmentalist contingent (which is not the majority to be fair) is, well, insane! Some animals only exist because they're kept as pets, can't make it in the wild and/or live longer, healther lives in captivity!