What do you think of animals in zoos?

I have to write a paper on this and was wondering on what others thought. I really don't think it is right, they are living beings like you and me, yet it is wrong if I lock another human in a cage. Unless it is to save the animal's life, we have no right to do this. I went to the petting zoo at the fair a few weeks ago and they had a kangaroo pinned in a cage so small that all it could do was lay there and it looked so sad...I mean this is wrong! What do you say?