Who is the bigger bioterrorist, man or nature?

Nature “Engineering H5N1 avian influenza viruses to study human adaptation”

I think that the most interesting idea expressed by this article is:

There is so much in this single statement, so many assumptions about the nature of humanity. While it is undoubtedly true that nature has traditionally been our biggest adversary, the question at hand concerning bird flu research is whether or not particular humans with malevolent intent are more likely than nature to spark a pandemic. Beyond the fact that it is modified nature (in which humans live at unbelievable densities and raise birds for food at even more unbelievable densities) that poses the real threat, I also think that it is a bit naive to compare a stochastic process in which nature might produce a pandemic version of this virus with the biosecurity dilemma, which has its chance elements but is far more deterministic.