[Doctor Stochastic]

If he had stole 80kg from Canada, that would be more believable. Terrorism works best on the gullible who will panic at any hoax. (Send me $100 and I will bring back the Moon.)

[No Blue States]

It seems like a dirty bomb is too complicated (and heavy)compared to anthrax and other chemical and biological weapons that are easier to secure, transport, and disperse.
That speculation on my part, or wishful thinking.