Hate to jump in on such a spirited conversation, but if anyone is truly interested in keeping sharks in an aquarium, might I suggest an online resource:
A unique forum soley dedicated to the captive keeping of Sharks & Rays in the home aquaria.
www.tapatalk.com
Shark and Ray Central. Been around forever, quite informative. Folks that know the answers, and have kept sharks (and rays) in captivity themselves.
For instance, in their shark care profiles section, on the brown banded bamboo shark (Chiloscyllium punctatum), that absolute minimum tank size for a single average sized adult would be a footprint of 50 sq ft. A tank 10' x 5' x 2', or a pond of 8' diameter, a minimum volume of 750 gallons.
Oh, and no, I've not kept any sharks, but I have done some research into what it would take to set up a shark tank. I may one day decide to do so, but if I do, it will be with enough research to give me a reasonable chance of success.