We live in the information age, which is called that for the same reason the ice age got its name: an overwhelming proliferation of the stuff. We automatically assume that more information is better than less. But as the dinosaurs learned about ice, even something useful can be dangerous in excess. The lesson is, so far, lost on most lawmakers and regulators. In July, President Barack Obama signed a bill requiring foods containing genetically modified organisms to be labeled as such. It's an outwardly innocuous requirement that is supposed to leave consumers better informed but will actually cause many...