In Cayman, we have one of the most popular feeding dives in the entire Caribbean - Stingray City. There has never been any confinement of these animals, and the chumming that initially attracted them was not intentional.
Stingray City started with the local fishermen anchoring inside the reef in North Sound to clean their catch. Various unwanted bits of fish guts and such would be tossed overboard. The stingrays gathered to take advantage of a free meal, which generally frightened the fishermen.
Pat Kenney and Jay Ireland, then working at Bob Soto's, started snorkeling this area during surface intervals between dives. Eventually, they decided to try hand feeding. It was a long time before the rays would approach, but eventuallythey took to hand feeding.
The research that has since been done on southern stingrays, and the countless interactions have now long dispelled the fears related to these fish.
But on the flip side, shark feeding was (and perhaps still is) going on. It was outlawed in Cayman in January of 2002. Rumor has it that certain operators may be continuing to run shark feeding dives. The power of the almighty dollar? No research. No substantial education. Not worth it.