“Many, indeed most, of them seem to be more concerned with the public relations impact of what they, or others, say and write, than in making sure that the facts are presented with complete scientific objectivity.”

One problem is that society has never agreed on a standard of what is safe in these surreal realms when the odds of disaster might be tiny but the stakes are cosmically high. In such situations, probability estimates are often no more than “informed betting odds,” said Martin Rees, a Cambridge University cosmologist, the astronomer royal and the author of “Our Final Hour.”
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Adrian Kent, also of Cambridge, said in a paper in 2003 reviewing scientists’ failure to calculate adequately and characterize accurately risks to the public, that even the most basic question, “ ‘How improbable does a catastrophe have to be to justify proceeding with an experiment?’ seems never to have been seriously examined.”
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Besides, the random nature of quantum physics means that there is always a minuscule, but nonzero, chance of anything occurring, including that the new collider could spit out man-eating dragons.
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Doomsday from particle physics is part of the culture.
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Some physicists, who have been waiting 14 years for the new collider, have proclaimed in papers and press releases increasingly ambitious and unlikely hopes, including proving a long-shot version of string theory by producing microscopic black holes.
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Cern’s most recent safety report, in 2003, focused mostly on refuting the strangelet threat in the hadron collider and devoted just three pages to black holes, saying they “do not present a conceivable risk.” It gave no odds. An anonymous Cern committee is working on a final, more comprehensive report.
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One popular option to determine acceptable risk is to demand that the chance of a man-made disaster be kept below the chance of a natural disaster like being obliterated by an asteroid. Astronomers estimate that chance as one in 50 million in any given year.
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Of course, thanks to those pesky quantum laws, disaster could come anytime. Or not. It could happen that the scientist’s prayer will be answered and your discovery will indeed lead to knowledge, human happiness and a new killer ap for iPhones.
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“As in all explorations of uncharted domains, there may be a risk,” Dr. Rees wrote, “but there is a hidden cost of saying no.”
 

http://www.nytimes.com/2008/04/15/science/15risk.html