You raise a very good point that can be applied to a lot of situations - such as reasearch or inventment in infrasturcture or even whether or not to go to war (ex. Iraq) - but most people are terrible in assessing risk, we are comfortable with huge familiar risks like getting in a car accident, getting cancer or getting shot by a gun and so underinvest in efforts to mitigate them, while unfamiliar risks are highly overweighted (radiation, plane crash, terrorism) - needless to say the people in power understand this, they hype the obscure risks that can lead to profit (defense, homeland security) and fight like hell against anyone who trys to point out an "everyday" or long term risk that can be mitigated (lung cancer, seatbelts, global warming, motorcycle helmets, vaccines) but might cost them. It is funny that even the terrorism risk is really just being afraid of a label, every few days we have the eqivalent of hundreds of small scale terrorist attacks, i.e. shootings in malls, public places, street corners etc... yet we ignore them - whereas if a guy with a foregn name did the same thing the media would go apeshit about it...