Following the Soviet collapse, the 50,000 workers drifted away. What with possible rogue scientists, designer germs, and the usual homicidal zealots on the prowl, lots of people are quaking in their Hush Puppies. Personally I'm not seeing it. I've yet to hear a convincing explanation of what the Soviets planned to do with their biological weapons. The U.S. dismantled its own germ-warfare program in the early 70s, partly because of protests but also because the stuff's value as a weapon was limited.
Germs are unpredictable and a bitch to work with.
Besides, while a couple mopes with a high school education can make a bomb powerful enough to blow up a government building, for a credible bioweapon you need a team of PhDs. There've been only a few known bioterrorist assaults. Ironically, the worst incident may have been an accidental anthrax release from a Soviet bioweapons facility near Yekaterinburg in 1979. In light of this spotty record, it seems clear only a crazy person would try a bioterrorist attack. If you've got enough on the ball to carry out a biological attack you're smart enough to realize that there are easier ways to achieve the same result.