Regulations to make peope responsible owners and do things right. I don't think some regulations would be bad. Some animals can be dangerous(IMO).
Did someone say mountain lion? Uh, I have small children.
Venomous snake? You crazy! LOL I know some of you have them. Be careful!
Very hard to make every one happy. But, I don't want a venomous snake to escape into my neighborhood and bite a unsuspecting person.
So, maybe there needs to be a reg/requirement for the type of enclosure you can keep a hot in. Just roll it around.

I hate the extremes! I can't imagine a world where a person can't keep a gold fish.

Assault weapons. There was a time before gun powder. Plenty of killing went on.