Lynn, the technological cat is out of the bag. In fact, they are relatively easy to manufacture and deliver. Many people are unaware that BW can be made by one or a few people, a point which I make in my novel, Death For Cause. This book started out as a scenario written to show US Government policymakers how serious the biological threat is. The knowledge that is necessary to making vaccines and conducting bio-medical research is the same as that used for making biological agents.
Chemical agents are somewhat more difficult to make.
But, as Aum Shinrikyo proved, they can be manufactured in a small space the size of a walk-in closet, using equipment and materials available commercially. Given that the knowledge cannot be squelched, it is important that we not mistakenly assume that clamping down on the Internet would help. It will not. The only things that will help us meet the challenges of CBW are to work hard on developing technologies to detect the presence or use of CB agents, and to help prevent or mitigate the effects of such weapons. Additionally, it is important to support law enforcement's efforts to prevent terrorists from using these weapons, while preserving as much privacy and freedom for innocent citizens as possible.