That's why the terrorists were exploring flying crop-dusters to disseminate it; it's a deadly weapon.
If there was one Iraqi ordered to do this, I wonder how many others are out there?
Not brain dead at all, good question. Here's a non-expert answer with the usual disclaimers: AFAIK it's deadliest if you inhale the spores and the spores are very persistant with a long dormant life; that's what killed people in the US mail attacks which we still apparently have no clue as to who did it (shouldn't the FBI do a genetic match on this to the mail anthrax??). It can also make you real sick if you swallow spores or get them through a wound. But the heavy killer is respiratory anthrax, which requires inhalation.
It's not known to be contagious at all person to person and it's curable with antibiotics. This makes it a little less scary but more usable as a weapon because it's more manageable.
Smallpox on the other hand is way contagious person to person and there's no cure. Which is why I would get a smallpox vaccination tomorrow if I could.
Corrections welcome. I don't claim to know what I'm talking about.