Animals in zoos, captivity, ect.

How do you feel about animals being in zoos, kennels, general captivity, ect.?
Do you think that it is fair to them, or should they remain wild? What about if they have to be taken in because they cannot survive in the wild for whatever reason; should they rough it out and let fate happen or should you help them?

That's a hard question. I don't believe in animal captivity but if the animals hurt or kill each other maybe it would be better.