Who is responsible for attacking several public figures with anthrax last year? We had the "terrorists did it" theory. We had the "Iraq did it" theory. We had the "rogue American scientists did it" theory. And now the Washington Post reports that everyone is baffled because the anthrax "recipe" used was very different than any known source of anthrax, domestic or foreign. The FBI is apparently sticking with the "domestic nutcase" theory, but that's complicated by the fact that the anthrax sample sent to Senator Leahy was ground more finely than even U.S. government laboratories had ever managed, which seems to point to someone with more resources than a single individual. This story isn't over yet.