[IP] more on NYC to search transit riders' bags -- but ...
Begin forwarded message:
From: Brad Templeton <btm@xxxxxxxxxxxxxx>
Date: July 24, 2005 5:08:38 PM EDT
To: David Farber <dave@xxxxxxxxxx>
Cc: Rick.Adams@xxxxxxxxx
Subject: Re: [IP] more on NYC to search transit riders' bags -- but ...
On Sat, Jul 23, 2005 at 10:20:31AM -0400, David Farber wrote:
If:
"truly random searches are likely to be more effective
than searches that follow a system."
then it clearly follows that systematic searches are likely to be
less effective
than random searches, which means that systematic searches will
likely perform worse than just getting lucky.
Somehow I continue to not be reassured...
Random or selected searches are not really a means of catching
attacks. They are a deterrent, or a means of increasing the
cost of attacks. If the attackers fear being caught, the random
search (or even the selected search they haven't figured a way around)
in theory should deter them from attacking at all -- if their view of
the risk of capture is high enough.
If they are suicide attackers, they don't so much fear getting caught
and punished as they fear wasting themselves/being wasted and attaining
nothing. One severeley hopes that suicide attackers are a scarce
resource for the terrorists(*). Random searches may convince them
to use those resources elsewhere -- which is about the most anybody
can do.
Random searches and a fast communications system could also prevent
the "coordinated" attack strategy, where the killers discover a
weakness,
and do several attacks at once, as in 9/11, 7/7, 3/11 etc. In
this case, if you send 20 armed hijackers on to planes, it's extremely
likely the random searches would find one of them, and sound the alarm
for greater scrutiny that stops all 20 of them.
(Consider that even if you search as few as one passenger in 30, the
odds
are 50-50 that you will find one, and then all, of a 20 person team. If
you search one passenger in 10, there's only a 12% chance the team of
20 could get through.)
In fact, only with non-random scrutiny can the team of 20 hijackers feel
they have a chance, something that's quite counter-intuitive. Once
the evil organization has identified 20 operatives who do not trigger
the flags of selective scrutiny, they can now mount their operation with
some confidence. With truly random selection they can not do this, it
inherently limits the size of the group.
(*)One of the most bizrre elements of London 7/7 was that the murderers
used suicide bombing when there is almost no tactical need to kill
yourself
to blow up a train compartment. It seems they were sent to kill
themselves
almost entirely for the shock value, and perhaps to make sure they
could not
be caught.
They seem to want to show us that suicide attackers are so plentiful
that
they can be wasted.
-------------------------------------
You are subscribed as roessler@xxxxxxxxxxxxxxxxxx
To manage your subscription, go to
http://v2.listbox.com/member/?listname=ip
Archives at: http://www.interesting-people.org/archives/interesting-people/