Hey Jeff, I thought the Tokyo subway was a chem attack, either Sarin or Ricin IIRC.

To the best of my recollection, there's not been a widespread bio attack in recent history. I remember there being a couple Anthrax threats a while back, but seemed like really isolated incidents through the mail.

Chem attack seems the easiest to me to deploy. It is too easy to make homemade substances that can poison people in an enclosed environment.

Still, this isn't really any different than what it has been for a long time now, just more publicity.