Slashdot Mirror
Feds Undertaking Massive Passenger Profiling Plan
Logic Bomb writes: "The Washington Post is running an overview of a rather big-brother-ish airline passenger screening system the government is proposing. Keeping track of people's ticket purchases is one thing, but correlating people's addresses and living arrangements...! This attempt seems closer to completion and implementation than any other that's been proposed so far."
Assurances from whom? The government? Trust us, we're from the government and we're here to help you. Not!
The often quoted (and probably inaccurate) statement attributed to Benjamin Franklin applies here : He that would trade liberty for security deserves and would receive neither.
It's all too easy to become complacent about trading away liberties until finally you have none. It's not that I think this particular issue is the end of the world, it's the principle of retaining and defending your right to privacy. All liberties must be defended vigorously, lest we allow the systematic elimination of them all.
Just my $.05 (inflation, you know).
-- "Other than that, how was the play Mrs. Lincoln?"
As an Israeli citizen, I can tell you we are less a police state than what the US has become.
Yes we have national IDs and soldiers and security guards everywhere, but we have freedom of speech (at least to some extent). I can buy/rent a zone 1 DVD at any video store. I can publish code to decrypt DVDs without any limitation. I can practice cryptography without being targeted. In Israel, the policial and social pressure groups rule and not the corporations. Here we have strict laws limiting campaign contributions.
Now, which country is more free?
Make even shorter URLs - 8LN.org
The problem with massive screening systems like these the reverend Thomas Bayes (of Bayes's theorem) is not the detection part, i.e. being able to actually detect all the bad guys, but not drowning in false alarms when doing so. And the base-rate fallacy says that there's not a whole lot you can do about it.
I've developed the argument further in an intrusion detection context see for example The base rate-fallacy and it's implications for the difficulty of intrusion detection, and it's directly applicable here. The article has an introductory example, that explains that under certain conditions a 99% accurate medical test, won't work at all. The references lists a few other papers by Matthews that are well worth a read also.
In short, since there are precious few passengers that are actually "terrorists" for any real definition of the world, the system must be several (perhaps 1x10^5 -- 1x10^6) times better at suppressing false alarms, than at detecting actual terrorist, to avoid the situation where "all" alarms (from a practical standpoint) are false alarms, i.e. the fact that you were flagged says nothing about you being a danger or not.
What's worse of course is that people when faced with such systems start to ignore their output sooner rather than later, and then the system becomes completely useless even from a narrow security perspective.
So, no, it won't work. It could have worked against the "casual" threat, its very existence could have served as a deterrent, but there are hardly any spur-of-the-moment suicide bombers, so, no, scrap that to. It can't work, because Bayes says so.
Stefan Axelsson