25 Mexicans are killed every day by guns purchased in the US. (Guns are illegal in Mexico but there are – rather conveniently – 6,700 gun shops along the Mexican border. All, of course, on the American side.)
The difference between our countries? Mexicans see the flow of drugs into the US as a problem, one they are trying to address. Americans, by contrast, don't see the flow of guns into Mexico as a problem and aren’t even trying to address it.
Here is an interesting article on President Calderon’s attempt to raise awareness of this.