RTC, arapaima and the alligator gar are the cursed fish on MFK. Once shown, be prepared that it will rain questions regarding tank size, pond and all your future plans on rehoming these fish. Do not be offended. Spend some more time here on MFK and you'll be sure to take constructive criticism from some of the members. Be prepared that there really are a few not-so-nice people here. ecoli up there is one of the nice guys, though. Most of the people here will be more helpful than just being fish nazis.
Back to the fish, it's more than likely that some people are really not prepared for taking care of such fish. Tank alone is just one of the issues. Filtration and food are next. How do you filter a multi-thousand gallon pond? I'm pretty sure that the bare minimum for an adult RTC is 4,000 gallons for life. How do you heat it up? Also, when in a pond, the RTC and all the other LARGE fish does not look as wonderful looking anymore. You'll be staring at their backs. The food will be very expensive for such a fish. Given all these scenarios that WILL happen, most RTC die of either abuse or neglect. I haven't even discuss their initial living conditions cramped in very small tanks. That's what most MFK members here are trying to prevent in the first place. We really don't know what can happen in the future. And oh, an RTC grows an inch per week on a very very good environment.