This may be painful news for the more control-freaky among us, but according to this article in Wired, those who disobeyed the authorities on 9/11 were "better informed and far more knowledgeable than emergency operators far from the scene."
In a connected world, ordinary people often have access to better information than officials do.
Not too surprising in today's Blackberry/cell phone world, but still, it doesn't seem right. At any rate, this doesn't mean planners can put their heads in the sand when it comes to risk management and contingency planning. If you haven't yet set up a system and protocols to handle the different types of emergencies that may come up during a meeting, don't wait. (To read more about what you can do, check out the articles on this site.)