One of the saddest videos I ever saw was a video taken at a circus. These elephants were performing, and one of them went berserk all of a sudden and started trying to escape, trampling over people, etc. It got out of the circus and the person with the camera continued filming as it ran down the street. The circus personnel didn't have any way to humanely control the elephant, so they all got out their rifles. The elephant was pinned up against a truck, and it took 40+ shots to the face before the elephant finally went down. And the whole thing was caught on film. I was horrified. The look in this elephant's eyes as it was dying was indescribable...
I am very much against making wild animals "perform" for the amusement of people. That's no way to treat such majestic creatures. They are deserving of our respect and shouldn't be treated as toys. Ever since I have been able to make decisions for myself, I have refused to attend circuses and shows that use wild animals for entertainment because of this.
You can't honestly say that people are able to keep an orca healthy and happy contained in such a small area for its entire life. That's worse than keeping a tang in a 10 gallon tank. The only time I feel it's okay to have these types of animals in captivity is if they have been injured or something, and they are unable to be rehabilitated and released back into the wild. But keeping healthy, functioning wild animals confined like that is just cruel to me.