People march demanding labels for genetically modified food near the White House in Washington, D.C., on Oct. 16, 2011. Ren Haijun/Xinhua /Landov hide caption

itoggle caption Ren Haijun/Xinhua /Landov

Farmer Alan Madison fills a seed hopper with Monsanto hybrid seed corn near Arlington, Illinois, U.S. A group of organic and other growers say they're concerned they'll be sued by Monsanto if pollen from seeds like these drift onto their fields. Daniel Acker/Landov hide caption

itoggle caption Daniel Acker/Landov