Half a billion eggs suspected of carrying salmonella have been recalled in what’s become the largest egg recall in U.S. history. And many people are wondering: How did this happen? Is it the fault of the factory farming industry? Or the government? And what can be done to prevent widespread food contamination from happening in the future?

The Wright County Egg company, based in Iowa, recalled 152 million eggs yesterday due fears of salmonella contamination. This brings the grand total to 380 million, after another recall back on August 13. Marion Nestle is an acclaimed nutritionist from New York University and the author of "Safe Food: The Politics of Food Safety." She says that this isn't the first time the Wright County Egg company has found trouble with the FDA, and that salmonella should not be difficult to prevent.