One would not normally expect anything of value to come out of rotten eggs. The case of the tainted Iowan shell eggs may well be the exception.
From an animal welfare point of view, cage free eggs are far from perfect, but they are better. And from a public health perspective, cage-free eggs are a necessary and urgently needed improvement.
Where were the inspectors? Why did it take local, state and federal authorities since May -- when the outbreak began -- to figure it out announce it to the public?