Here is an interesting article from The Skeptical Inquirer titled A Skeptical Look at September 11th How We Can Defeat Terrorism by Reacting to It More Rationally. Some excerpts:
I hope I didn’t over-quote and violate any copywrite laws–my goal was to pique enough interest to get more people to read it.
Thoughts on the article?
I think there is a basic flaw in comparing natural disasters to artificial disasters. It is the same difference involved in Grandma dying in pain from cancer and Grandma dying in pain from being beaten by the house maid.
There is a perpetrator, a human mind that did this. We can blame actual people and bring them to justice. In so doing, we may reassert man’s humanity. Though there are ways we may act to prevent natural disasters, we cannot bring tectonic plates or the influenza virus to justice, and they don’t have any sort of social contract with our society.
It is completely possible that we have spent disproportionally on security after 9/11, but I don’t think that assertion is backed up by the author’s use of natural fatality statistics. To me, the comparison isn’t valid.
Much of the blame for this effect has to go to mass media. The “national mood” is deemed to only be able to focus on a few things at once, and reportage clocks in accordingly. If news doesn’t neatly fit into one of several ongoing plotlines, it gets buried.
Another part of the blame has to go to apathetic souls who couldn’t care less about current events. Who has the time to look at anything in-depth or worry about the unfortunate?
More, still, must go to the herds that follow each “news event” as if it were more noteworthy than anything else.
Damn, I’ve just depressed myself. I don’t want to comment anymore. 
For a purportedly “rational” argument, the article misses a huge issue of fact - that uncertainty imposes greater costs than predictable events that inflict (individually or cumulatively) equal immediate damage.
Say in a particular area, the seismologists predict that once every 100 years there will be an earthquake that will kill as many as died on 9/11. People can take that information and make rational choices, based upon their interpretation of that risk. They may buy earthquake insurance, move elsewhere, or play the odds and assume that the earthquake won’t hit while they are living there.
Such assessments cannot be made with regards to large-scale terrorism. Insurance companies - who, at least in terms of insuring risk, define rationality (though on the financial/investment side, they are often idiots), are refusing to issue terrorist insurance, not because of the potential costs (even though they could be high), but instead because they lack the tools to assess the likelihood of an attack or the potential losses.
When faced with an uncertain but real risk of high damages, the rational response is to be overcautious.
The whole problem with the article can be summed up in this sentence from it.
As there has only been one large-scale terrorist attack, it is literally impossible to determine the numerical odds. So, while the statement is generally true, it has no bearing on the terrorist risk, because the odds have yet to be established.
Sua
Humans need to come to grips with that fact that bad things like accidents will take a lot of lives. Its a freak random thing and while it can be avoided we cant freak out about it everytime we hear a car screeching, or see someone smoking or pass by a hospital.
We do have to stand up and do something about murderers. The violation of thsi basic human right is an abomination and must be dealt with swiftly and decisively or it will happen again.
Death by accidents, sickness and natural disasters are inevitable. Murder is not and must be punished.
The subject of misjudging levels of risk is fascinating to me, and almost everyone, no matter how savvy otherwise, seems to have trouble rating risks. For example, in a conversation with an airline employee a few months ago, she extolled the virtues of her employer’s visibly decrepit fleet of aging, leased DC-9’s, then pointing to one of a competitor’s nearly new Canadair Regional Jets, said “You’d never get me up in one of those little things, they’re too small.” The fact that the example CRJ was much further away from the end of its fatigue life, only slightly smaller than a -9, contained much more advanced engines and equipment, and was otherwise the same configuration apparently meant nothing to her.
Re: the OP, after a quick skim, I agree with most of the article, although I don’t buy the comparison with natural disasters. For months in private discussions I’ve been saying that the amount being spent on response to the 9/11 attacks is disproportionally large. If there were such a statistic as ‘total amount of money spent per life lost’, including the cost of all the increased security measures (and the cost of the invasion of Afghanistan, since that would likely never have occurred without the impetus of 9/11), I wouldn’t be surprised if these were the most economically costly fatalities in recorded history. OTOH, since we apparently are perfectly willing to spend these record amounts without complaint, I suppose it doesn’t matter.
[Minor, er, hijack]
Of course, once the various agencies and government security fiefdoms have been put in place, it is unlikely we will ever be rid of them. One way they will be kept in place is by misusing statistics to show that they remain necessary. My favorite example (I 've been wanting to do this for some time) is this graph from the Transportation Security Administration’s web site, showing that from February to September of this year, more than 3 million proscribed items were confiscated from airline passengers (note that, presumably due to public interest, “boxcutters” are shown separately from “knives”).
So does this mean that 3 million attempted hijackings were thwarted during this period? Of course not. Were any attempted hijackings thwarted during this period, through the confiscation of these objects? Don’t know, doesn’t say; but I would presume if any had, the agency would have said so. So, 3 million items were confiscated and zero hijackings were thwarted. Value for money? Fucked if I know.
[/Minor hijack]