Project Gunrunner is a project of the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) intended to stem the flow of firearms into Mexico, in an attempt to deprive the Mexican drug cartels of weapons.The primary tactic of Project Gunrunner is interdiction of straw purchasers and unlicensed dealers to prevent legal guns from entering the black market; between 2005 and 2008, 650 such cases involving 1,400 offenders and 12,000 firearms were referred for prosecution.