Richard A. Serrano
LA Times 
July 17, 2011
Congressional investigators probing the controversial “Fast and Furious” anti-gun-trafficking operation on the border with Mexico believe at least six Mexican drug cartel figures involved in gun smuggling also were paid FBI informants, officials said Saturday.
The investigators have asked the FBI and the Drug Enforcement Administration for details about the alleged informants, as well as why agents at the Bureau of Alcohol, Tobacco, Firearms and Explosives, which ran the Fast and Furious operation, were not told about them.
The development raises further doubts about the now-shuttered program, which was created in November 2009 in an effort to track guns across the border and unravel the cartels’ gun smuggling networks. The gun tracing largely failed, however, and hundreds of weapons purchased in U.S. shops later were found at crime scenes in Mexico.
The scandal has angered Mexican officials and some members of Congress. Investigators say nearly 2,500 guns were allowed to flow illegally into Mexico under the ATF program, fueling the drug violence ravaging that country and leading to the shooting death of a U.S. border agent.