A lone milkman is delivering misery to the doorstep of the giant dairy industry. Hein Hettinga was once a simple dairy farmer who sold raw milk from his farm in Chino, Calif. Today the Dutch immigrant has expanded his operation so much, so fast, that some of the biggest dairy companies and cooperatives in the U.S. have banded together against him. They are lobbying for federal laws to close loopholes they claim he exploits. Mr. Hettinga counters that the only purpose of the proposed legislation is to kill competition -- and keep milk prices high. "That's not right," says the...