Maybe $ were the motive.....not terror.
All someone had to do was open a window in Manhattan......If they were trying to terrorize.One of the theories why the anthrax attacks ended is that Atta took the remainder of it with him, intending to spread anthrax around the WTC crash site. The '93 WTC bomb included poison, which burned up in the explosion. Multi-layered attacks are part of the Al Quaida playbook (doesn't mean they succeed). At least one suicide bomb in Israel also carried poison.
And while it didn't kill a lot of people, the anthrax did contaminate a lot of Post Office equipment and facilities. Keep in mind they could not do a test run, so beginner's luck was their only real chance of killing a lot of people. Nobody had ever tried that many simultaneous hijackings either.
It also fits the longstanding Al Quaida pattern of not taking credit for attacks.
I know it's much more appealing to ignore the evidence of your own eyes and twist your brain into pretzels to come up with some convoluted theory about this, but how about we just try taking the letter at face value for a second? This really isn't a very complicated problem.
The first thing you have to do is get it into your head that this letter, accompanied as it was by high-grade, weaponized, aerosolizable anthrax, represents a credible threat to kill millions of people. I know that the anthrax story was managed in such a way as to distract you from that reality but, nevertheless, it is the reality.
The second thing you have to realize is that the boast "YOU CAN NOT STOP US" is entirely plausible, and would be recognized as such by the national command authority, the real target of this message. The anthrax emits no tell-tale signal, it takes up no space, it can be delivered by hand with devastating effect -- for example, a few bags of this stuff surreptitiously dropped on the NYC subway tracks would turn Manhattan into a worthless patch of uninhabitable waste ground overnight.
Then, you have to ask yourself, why would a "loose-knit, widely-dispersed" band of terrorists issue such a threat, instead of using the anthrax to kill as many people as possible? The answer is that the notion of "loose-knit, widely-dispersed" network of muslim crazies carrying out sophisticated terrorist attacks is a fable conjured up by the Clinton administration to avoid the unpleasant choices that would be involved in going after the real organizer and sponsor of these operations, whose initials are SH.
Iraq is the only hostile country known to have succeeded in turning anthrax into a viable weapon. The US biowar program is largely predicated on and driven by the threat presented by Iraq's anthrax capability. Coincidentally, Iraq's government is also the only government to have endorsed Osama bin Laden and the attacks on the World Trade Center, the only government whose talking points feature regularly in OBL's communiquees, and the only government known to have directly liaised with Mohammed Atta, and the only government to harbor an indicted conspirator in the original, 1993 attempt to topple the WTC towers.
It doesn't take a rocket scientist to figure this one out, my friends.