I can't speak for all the " Swim with the Dolphin" places as i have only been to the one that is located in the Fla. Keys. MM88 I think ( I can't remember the name of it. ) It has been a few years since My wife and I went.

I found there program to be very caring of the Dolphin. We were instructed on how NOT to interact with them. We were told that touching thier heads was a definate NO NO. we were also told that the interaction would be at the Dolphins initiation and not ours.
Altho they brought us to the area as a group. The aomunt of people allowed in the water with the Dolphins was limited to a few at a time , 4 or possibly 6 .

I can definatley see where these wonderful animals can be exploited. However I did not see any of that at this organization. The experience was one of the most wonderful things I've ever done in my life. I would recommend it to anyone. But with a caveat. Check out the place first. Ask ,if possible, other people who have used the facility.

I have been to the Belize one off Spanish Lookout Caye. It is well done as far as these things go. I am still not for it but they seems to have some good professionals running it, working with the dolphins, etc. VERY controlled interactions with the dolphins. Not sure if it is open to the public yet.
http://www.belizeadventurelodge.com/dolphin_experience.html