I thought the metaphor was clear - society, as a whole, is not threatened by this sort of thing, and it is not even particularly dangerous from an expected value perspective. The point is not that nothing should be done - as I mentioned with my reference to hygiene precautions. Washing your hands and encasing yourself in an antiseptic bubble are two <i>very different things</i>, and the fact of the matter is that <i>not all deaths are preventable</i>. I was trying to make the point that the knee-jerk reaction of &quot;something should be done&quot; discounts the possibility that sometimes it&#x27;s not worth it to do anything, either because additional action would have no effect or because the marginal cost of that action exceeds the benefits.<p>A fairly large number of people die from influenza every year, but we don&#x27;t have a mass surveillance dragnet to try and isolate flu vectors, <i>for good reason</i>. We do, however, have a fairly robust vaccination system which is a <i>sensible precaution to take</i>.