To make another comment on this topic I think with social media and forums like this us as fishkeepers need to show that we are responisble care takers of our fish. There are a lot of memebers on here with over stocked tanks but due to the amount of work they put into their tank with maintence they make it work and the fish live a good life. A lot of memebers on here take care of their fish better than a lot of people take care of themselves. I think if we could have a voice in things an expose this to animal advocate groups it may change a view on things.
As for permits for keeping fish it would be a nightmare. If the municipality that you lived in adopted an ordinace for pet inspections things could get interesting. For an example say you live in Plymouth township and I live in Norristown Borough and we both keep fish in a 125 gallon tank. For inspections my borough adopted the basis for fish keeping is the classic petsmart 1" of fish per gallon rule while your township adopts the sceintific formaula to calculate how many or how large of a fish or fishes you can keep. So obviously as you can see the stockes would be extremely different and a lot of the larger species of fish we keep would not be allowed. My point is this would ruin the hobby and extremely limit people to what they could potentially own. And if at a national level a certain standard is adopted on how to stock your tank and how many or how big of a fish your tank can hold I think the hobby would crash.