By Fred Burton and Scott Stewart In a case built largely on the use of a planted informant, a federal jury in Sacramento, Calif., on Sept. 27 found environmental activist Eric McDavid guilty of conspiring to damage property by using explosives. McDavid, 29, was accused of planning to use improvised explosive devices (IEDs) to damage the U.S. Forest Service Institute of Forest Genetics, the Nimbus Dam, cellular telephone towers and electric power stations, among other targets. McDavid's two co-conspirators, Zachary Jenson and Lauren Weiner, had pleaded guilty to conspiracy charges and agreed to cooperate with the government in its prosecution of McDavid. McDavid, Jenson and Weiner were arrested Jan. 13, 2006, after they had scouted a number of potential targets and begun to procure chemicals to manufacture improvised explosive mixtures.