http://www.straightdope.com/classics/a1_051.html
As far as weaponry acquisition . . . it's difficult to separate fact from fiction. Dredgereport.com gets a lot of wire information, but how reliable? What's the 'byline bias' from foreign wire services? What's the degree of intent for delivery, etc? There's a lot of variables involved.
The strongest point, in my opinion: if you look at the sheer physics of the thing, it's difficult and extremely dangerous to outfit these sort of biological/chemical/even nuclear weapons for delivery. Not the sort of thing that can be done in a low-tier lab, not to mention a set of tents in a cave, so as to hide from satellite imaging . . .
Bottom line: I'd say it's somewhat normal to think of these things, examine the possibilities, etc - it's dangerous to get wrapped up in them, especially when they could potentially be such remote possibilities.