Our topic today is science and censorship.  The case of smallpox provides an interesting case-study.

Smallpox, once a main scourge of mankind, was eradicated through the efforts of the World Health Organization and others.  Stocks of the virus were retained by the U.S. The U.S. and the Soviet Union retained stocks of the virus in Atlanta and Siberia. 

Now, however, the smallpox genome has been sequenced and is on the web.  In the words of Antointe Danchin, Director of the HKU-Pasteur Research Center in Hong Kong:

We thought we had eradicated smallpox, but now that its sequence is on ethe Web, it is more of  a threat than ever, freely available for anyone to download and manipulate it.  And the damage has been permanently done, all becasue of the vanity of soem irresponsible scientists...
("Not Every Truth is Good," European Molecular Biology Organization Reports, 2002)

This seems, prima facie, like a terrible thing.  Perhaps there is another side to the issue.  It's unclear to me what it might be Danchin had argued to prevent the sequencing of the genome; he notes that the reasons cited against his campaign were all-purpose homilies:

...knowledge should not and cannot be suppressed; nobody knows whether there are hidden pools of the virus; se should preserve our knowledge of biodiversity, and so on.  My contention is simple:  we should have destroyed the stocks of the virus, and w should not have sequenced its genome.  It is a fallacy that all knowledge is good.  The virus has only one host---man.  It therefore cannot re-emerge and so surely it is more important to destroy it than to understand it.  ... many species become extict every day without their genomes having been sequenced.  Finally, there are more tan enough current and new diseases to absorb our research efforts once we have unequivocally abolished this one.

It is of course conceivable that it will turn out to be a good thing that the sequencing was done and made available on the Web.  Any philosopher worth his or her salt could come up with some scenario.  But the probabilities seem overwhelming that it was a bad thing.  Should it have been prevented?

Preventing the publication of the sequence on the web would have required censorship.  And the question is always, who should be the censor?  Ideally scientific organization would take on this duty, using persuasion and soft constraints, like treating scientists who do such things with contempt.  But this doesn't seem to be happening.

That seems to leave governments.  I don't like the idea of governments censoring things, but it seems quite inconsistent to give governments the power to bug our phones, incarcerate people indefinitely, and invade other countries, all to lessen the dangers of terrorism, but deny them the power to publish virtual manuals for terrorists on the web.

But earlier intervention seems appropriate.  I don't know the details in this case, but I suspect the sequencing of the smallpox virus was in some way subsidized by governments, probably ours.  President Bush, with respect to stem-cell research, invoked the principle that the government should not subsidize immoral research.  Whatever the merits of his argument in the stem-cell case, the general principle seems correct.  It should be invoked in more clear cut cases.  As I write government money, taxpayer money, is being used to invent "improved" thermonuclear devices, and probably better land mines and all sorts of other nefarious weapons, that, if history is any guide, will end up in the "wrong-hands" (and, by my lights, starts off in the wrong-hands in any case).

To presever Millian principles of free-inquiry without acquiescing in  insanity like publishing the smallpox sequence on the Web, we'll have to understand those principles and their conceptual limits better than we do.  Plenty of work here for philosophers.  For those interested, Philip Kitcher's Science, Truth, and Democracy (2003) is an excellent place to begin.