Paul:
It is not only insane but inhumane. I have looked through several sources on the keeping of Xenopus. Most sources seem to allow a little more than a gallon per ACF. I have seen one source that recommended that you can put 6 frogs in about 4 gallons of water The folks at Xenopus Express seem to be the most resonable, allowing 5 gallons per frog (which I agree with), their reason is that these frogs like to swim.
I can imagine that since ADFs are smaller, you can put them in a pint of water. Gosh, I don't put my Bettas in that little amount of water. I don't understand how people can get away with this.
Aquatic frogs are tough animals and can survive extreme conditions. Amphibians are cool animals and deserve our respect and proper care.