A disease like the Black Death killed anywhere from a third to two-thirds of the population of Europe. What if something like that were artificially created--just "to study"--and escaped into the wild? Is that kind of accident ever justified? We're talking about horrible diseases that would not even exist except for our tinkering. We've resurrected the Spanish Flu from the permafrost. We've created super strains of the H5N1 avian flu that are lethal and easily spread and that no human has any immunity to. And I'm just talking about academic/university labs, since those seem the most vulnerable to accidents (but maybe that's only because those accidents are more likely to be reported than accidents in government/military labs?)

The world faced a similar decision point after the Fukushima meltdown in terms of risk/benefit. Advanced countries like Germany and Japan have essentially turned away from nuclear power as a result (although we'll see if those decisions can endure in light of our power needs and energy costs).

The movie Contagion touched on this issue, too. If you remember, the CDC told an academic researcher to shut down his lab's work on the influenza virus once they determined how deadly it was so the work could be moved to a highly secure lab. Yes, they could work faster than a more secure lab, but at what risk of it getting out in a different location and sparking a new epidemic? It's a question that is always hanging over this kind of work.

Edit: Before I come across as totally anti-science, I just wanted to clarify that I don't mean this issue to be all-or-none. As the article points out, since history has shown that it is "when" not "if" these organisms get out, perhaps there should be more debate about whether certain organisms should not be handled in the lab in the first place. For example, there was quite a bit of debate in the scientific community whether work to create a super strain of H5N1 should take place at all because of the risk of an accidental release into the wild.