http://www.miamiherald.com/2011/04/08/2157694/white-powder-found-congressmans.html#ixzz1Iy3JXUDhIt does say that they decided it's not Anthrax already; because, you know, Anthrax is the only dangerous white, powdery substance on the planet.
I also get the feeling that this has become some sort of "cool" protest. Mad at a politician? send him some flour in an envelope, because that's not
actually a death threat or anything. This kind of all or nothing, we win or you deserve to die rhetoric (from either side) pisses me off. I hope when they find whoever sent it they hang him.
Just for fun, when they come up with a suspect, that's compare him to DHS' domestic terrorist checklist from the other thread.