Because the stuff has to be inhaled to be deadly...subcutaneous anthrax is for the most part, cureable. Inhaled, on the other hand, is mostly fatal. That's why the people handling it (post office/mail room workers, etc.) lived, while the people that opened the letters (who inhaled the particles) died.

This guy knew exactly the kind of panic he was creating. He was a bitter scientist. He preyed upon the panic of 9/11 by creating more panic. He spent WAY too many afterhours in the lab, and was the only person dealing with this strain of anthrax. How is it possible that someone else in another place could've had THE SAME EXACT STRAIN? That's like telling me that someone across the country has the exact DNA as you. Puhleez.