I believe the term is "cognitive dissonance". I recall reading a lot about it in Barbara Tuchman's book "The March Of Folly."
So these announcements are preparing you so that you will believe it.
Here's what I put on my web site about that yesterday:
September 27, 2006(A) - I was contacted by a couple science reporters yesterday, both looking for some sinister and hidden meaning behind Dr. Beecher's article. One of the reporters pumped me on the phone for about 15 minutes, trying to get my feelings as to why the FBI would release such information. My answer was just a guess: The media has built a wall of nonsense and misconceptions around the true facts of the anthrax attacks, and the FBI is most likely trying to break down at least some of that wall. I wouldn't be surprised if there weren't more such articles. The wall of nonsense and misconceptions created by the media is pretty tall and solid.
Why would the FBI want to break down such a wall? My answer is just another guess: To create a public and scientific atmosphere where facts instead of fiction can prevail.
Ed