Lots of great points in this thread, it's been a very interesting read!
Here's my take on keeping all animals. It is (or should be) the individual's right to own that animal. However, it is (and/or should be) the individual's responsibility to properly care for that animal, and to keep the general public out of harm's way of that animal.
With most animals, you're not talking about any risk at all - however there are a select few where this plays in.
Big cats, bears, crocodilians, large primates (all apes, plus the larger monkeys like macaques and such), elephants, and a few others that you could in theory get if you REALLY wanted to, all could be considered dangerous. We may want to include large constrictors and venomous snakes as well, although the risk is far lower.
As with all animals (again, IMO) - every individual
should have a right to keep these creatures. That is IF AND ONLY IF - they can properly care for them, and they are able to absolutely keep the public out of harm's way from these animals.
Being able to properly care for these animals means a steady year-round food source, adequate space, ESCAPE-PROOF HOUSING, a certified veterinarian, and mental stimulation, to name a few. Keeping the animal cared for goes hand-in-hand with keeping the public safe - the animal is not well cared for if it is able to escape from its cage in any way, shape, or form.
How do we determine if somebody is capable of caring for these animals? Well, this is where it gets tricky. Most of this is opinion - so if we were to actually create a law on this matter, we would need to create a panel of people who have cared for these animals (aka experienced zookeepers of a high ranking), and get them to agree upon something that is considered adequate.
Then we would need Fish and Wildlife (most likely) to send out people to inspect enclosures for these animals and everything, to ensure they will be properly cared for. The owner would pay for these visits, they could happen once a year, twice a year, however often.
I will say this - that would deter everyone BUT the hardcore enthusiasts from keeping these animals. And those hardcore enthusiasts are exactly the people that should be allowed to keep these animals - they will be willing to put in the time and the effort to properly care for them.
And yes, there are people out there that can properly house these animals. It's the same way with sharks - you wouldn't think there are that many people out there that can house a 6'+ shark, but there certainly are. It can be done for much cheaper than most would think, you just need to know the tricks of the trade
Sorry for the wall of text, hope someone enjoys it. Great thread!
Drew