You've heard this shocking "fact" before — on TV and radio, in newspapers, on the Internet and from the highest politicians in the land: 90 percent of the weapons used to commit crimes in Mexico come from the United States. - Secretary of State Hillary Clinton said it to reporters on a flight to Mexico City. - CBS newsman Bob Schieffer referred to it while interviewing President Obama. - California Sen. Dianne Feinstein said at a Senate hearing: "It is unacceptable... (GunPolicy.org)