He says the similarities he sees are "unnatural and contrived" in the way the Hebrew characters were drawn, and this evidently indicates to him that the writer of the anthrax letters was trying to deliberately draw characters that resemble Hebrew characters in an "unnatural and contrived" way. Some of the characters he has mentioned are drawn using the formal calligraphy style called "Ashuri" and some are drawn using the informal script or "cursive" style as shown in the illustration above. The anthrax letter sent to Tom Brokaw is shown below. (You can click on any of the illustrations to view larger versions).
Here are some details about the Anthrax Truther's "hypothesis" or "theory":
The Anthrax Truther's third claim is that the way the I and C are drawn close together in the word "AMERICA" is an "unnatural and contrived" way of drawing the Hebrew cursive letter Aleph. Of course, it could also be that that particular "I" was simply drawn a bit too far to the right, which is perfectly natural for a human being who does not print like a machine. The Anthrax Truther's "logic" is illogical.
The Anthrax Truther's fourth claim is that the G in GREAT looks like an "unnatural and contrived" way of drawing the cursive Hebrew character Tet. Actually, to most people the G probably looks more like the number 6 than the Hebrew character Tet. But, the Anthrax Truther argues that the differences between the G and the cursive Tet are evidence that the writer was drawing a Tet in an "unnatural and contrived" way, instead of simply drawing a G in the writer's natural style. The Anthrax Truther's "logic" is illogical.
The Anthrax Truther's fifth claim is that the question mark in the Senate letter is an "unnatural and contrived" way of drawing the cursive Hebrew character Kaf. Why anyone would draw a Kaf (which is pronounced like the K in King) where a question mark should be is undoubtedly the Anthrax Truther's proof that it is "unnatural and contrived." But, to anyone else looking at it, it's probably good proof that the Anthrax Truther's "logic" is illogical. His theory is unnatural and contrived. He's making connections where there almost certainly are no real connections. According to Wikipedia, someone writing in Hebrew who wants to write a question mark will write it the same way as it's written in English.
The Anthrax Truther seems to believe all this "unnatural and contrived" writing of pseudo-Hebrew characters was done to mislead the FBI into thinking Israelis were behind the anthrax letter attacks. The Anthrax Truther clearly sees no problem with believing at the same time that writing the phrase "ALLAH IS GREAT" in the letters was done to mislead the FBI into thinking that the attack was done by Muslims.
On the other hand, to me it seems that the entire Hebrew alphabet may simply look "unnatural and contrived." Who creates an alphabet where so many characters look so much alike? The Daled merely has a slightly shorter vertical line than the Khaf, and both are similar to the character Reish, except that the Reish is drawn with a single stroke. And, what's the difference between a Samekh and a Mem Sofi? And look at Chet, Hey and Tav. And Beit and Kaf. One would think that over the course of 2,400 years, someone would have come up with something better! (That's a joke, folks.)