Editor’s note: Bruce Schneier is a security technologist and author of “Liars and Outliers: Enabling the Trust Society Needs to Survive.”
It’s an old song by now, one we heard after the 9/11 attacks in 2001 and after the Underwear Bomber’s failed attack in 2009. The problem is that connecting the dots is a bad metaphor, and focusing on it makes us more likely to implement useless reforms.
Connecting the dots in a coloring book is easy and fun. They’re right there on the page, and they’re all numbered. All you have to do is move your pencil from one dot to the next, and when you’re done, you’ve drawn a sailboat. Or a tiger. It’s so simple that 5-year-olds can do it.
But in real life, the dots can only be numbered after the fact. With the benefit of hindsight, it’s easy to draw lines from a Russian request for information to a foreign visit to some other piece of information that might have been collected.
Opinion: Agencies often miss warning signs of attacks
In hindsight, we know who the bad guys are. Before the fact, there are an enormous number of potential bad guys.
How many? We don’t know. But we know that the no-fly list had 21,000 people on it last year. The Terrorist Identities Datamart Environment, also known as the watch list, has 700,000 names on it.
We have no idea how many potential “dots” the FBI, CIA, NSA and other agencies collect, but it’s easily in the millions. It’s easy to work backwards through the data and see all the obvious warning signs. But before a terrorist attack, when there are millions of dots — some important but the vast majority unimportant — uncovering plots is a lot harder.
Rather than thinking of intelligence as a simple connect-the-dots picture, think of it as a million unnumbered pictures superimposed on top of each other. Or a random-dot stereogram. Is it a sailboat, a puppy, two guys with pressure-cooker bombs or just an unintelligible mess of dots? You try to figure it out.
It’s not a matter of not enough data, either.
Piling more data onto the mix makes it harder, not easier. The best way to think of it is a needle-in-a-haystack problem; the last thing you want to do is increase the amount of hay you have to search through.
The television show “Person of Interest” is fiction, not fact.
There’s a name for this sort of logical fallacy: hindsight bias.
First explained by psychologists Daniel Kahneman and Amos Tversky, it’s surprisingly common. Since what actually happened is so obvious once it happens, we overestimate how obvious it was before it happened.
We actually misremember what we once thought, believing that we knew all along that what happened would happen. It’s a surprisingly strong tendency, one that has been observed in countless laboratory experiments and real-world examples of behavior. And it’s what all the post-Boston-Marathon bombing dot-connectors are doing.
Before we start blaming agencies for failing to stop the Boston bombers, and before we push “intelligence reforms” that will shred civil liberties without making us any safer, we need to stop seeing the past as a bunch of obvious dots that need connecting.
By Bruce Schneier , Special to CNN
May 2, 2013 — Updated 1437 GMT (2237 HKT) CNN.com
The opinions expressed in this commentary are solely those of Bruce Schneier.
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