Are We Paying Too Little Attention to the Bioterrorism Threat?

I am scared of bioterrorism. There seem to be so many ways to wreak mass devastation on humankind.



Here's just one example I've dreamed up. I am not a bioterrorism expert so, of course, it's quite possible that this wouldn't work.

And indeed I deliberately did not do any research on how to make the plan more viable. The last thing I want is to give some nut a plan that would hurt people.



But this scenario may give you some idea of why the government and private sector should make preventing/stopping bioterrorism much higher priority than it seems to be:



A professor specializing in bioterrorism is denied tenure in favor of someone s/he felt was much less competent, hard-working, and ethical. S/he knew that being denied tenure devastates your career.



In fury, she purchased  the highly-communicable, deadly smallpox virus. (I can't believe smallpox virus  can be purchased. Scary!)



On the day before harvest time, s/he went to a large orange farm that s/he knew distributed oranges all over the world and, in the middle of the night, injected smallpox (or some other highly communicable bioweapon that would remain viable in oranges) into a few oranges on each of the farm's hundreds of trees.



S/he knew those oranges would be mixed with the oranges grown by dozens of other orange farms and then distributed (as whole fruit and as orange juice) everywhere from Alabama to Wyoming, Azerbaijan to Zululand.



Within a few weeks, the top news story worldwide would be the unexplained cases of smallpox, that it was highly communicable and because the virus would already have had a lot of time to spread, it likely would be near-impossible to stop a worldwide epidemic.



And if the professor/scientist had sufficient expertise, s/he perhaps could have created a mutated version of the smallpox virus, for which there is no vaccine, making the epidemic even more devastating, maybe even killing a majority of the world's inhabitants.



Again, this is but one scenario that came off the top of my head. I can think of a number of others. Among the world's seven billion people, I'd imagine that at least one deranged but brilliant person could or already has come up with an Armageddon Plan that would actually work. 



Am I overstating the risk? Some reassurance please!