I hate to say I told you so. A few months ago I was asked to give a couple talks to the skeptic community. Since I had just published a book about viruses, I decided to talk about the way myths so often crop up around them, and how a properly skeptical person should think about viruses. Over the centuries, viruses have been encircled by urban legends, superstitions, and conspiracy theories. The name "influenza" dates back to a time when European physicians believed the flu was due to the influence of the stars. More recently, HIV has been subject to all sorts of myths, from stories that it was created by the CIA to claims that it is not the cause of AIDS. The autism-vaccine controversy has been fueled in part by myths about viruses--namely, that the risk from vaccines is far greater than the risk from viruses like measles. In my talks, I speculated that the very nature of viruses makes it easy for people to grab onto these kinds of explanations, and to reject scientific evidence that might argue against them. Viruses are the smallest living things on Earth, and yet they can have worldwide effects. They may only contain a few genes, yet they can hold their own against all of modern medicine. And the reality of viruses can seem downright unbelievable. Rabbits with horns may sound like yet another myth--but there's some truth at the core of it. So it may be psychologically easy to endow viruses with extraordinary powers, or to deny them any power at all. At the end of my talk, I told my audiences that we might be at the beginning of another one of these viral episodes. I described how a virus called XMRV had been recently linked to chronic fatigue, a debilitating condition that may affect 60 million people worldwide. Since the initial report, there had been some attempts to replicate the link, but they had failed. At the same time, some people with chronic fatigue decided the cause of their suffering had been found, and now the only course of action was to take drugs that could wipe out the virus. (Here's a good piece at the time from Ewen Callaway at Nature [free, reg. required]) In my talk, I said that even if the link was rejected, it had already found a community that would continue to embrace it. Since then, more studies have come out, and they've been so negative that many experts have concluded the initial link was a matter of contamination. And today in the Guardian, Robin McKie reports that XMRV proponents are now issuing death threats to scientists who have done this research. The scientists he talks to have some pretty startling things to say. A protestor shows up at a talk by a scientist, armed with a knife. A scientist backs out of a collaboration for fear of being shot. I should say I take this article with a grain of salt. McKie writes that "according to the police, the militants are now considered to be as dangerous and uncompromising as animal rights extremists." But the catalog of harassment he presents made up mainly of obnoxious emails. No one's bombed a lab. And even if there are some people who are sending XMRV-related death threats, they could well just be a handful of people, rather than any sort of broad movement. In other words, I really hope that my prediction turns out to be wrong. Update: Thanks to Vaughan Bell for alerting me to this British Medical Journalarticle by Nigel Hawkes in June on the same issue. Combined, the two articles become more worrisome. Update #2: With a fast-growing comment thread, I just want to remind everyone that, while I do not take responsibility for the content of the comments, I do moderate them according to my "light but firm" comment policy. A spirited debate is fine with me; it's fine for patients to complain about how they're treated by the medical community. But if (like one of today's commenters) you declare that a scientist has committed "a human rights crime" against patients, don't wait up tonight to see your comment come out of moderation. It won't. You're free to write the stuff on your own blog; I'm free to decide not to include it here.