Skip to main content

Why FBI and CIA didn't connect the dots

By Bruce Schneier, Special to CNN
May 2, 2013 -- Updated 1437 GMT (2237 HKT)
Police say the dead suspect, <a href='http://www.cnn.com/2013/04/21/us/tamerlan-tsarnaev-timeline/index.html'>Tamerlan Tsarnaev</a>, is the man the FBI identified as Suspect 1. He was killed during the shootout with police in Watertown, Massachusetts, on April 19, 2013. He is pictured here at the 2010 New England Golden Gloves. Police say the dead suspect, Tamerlan Tsarnaev, is the man the FBI identified as Suspect 1. He was killed during the shootout with police in Watertown, Massachusetts, on April 19, 2013. He is pictured here at the 2010 New England Golden Gloves.
HIDE CAPTION
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
<<
<
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
>
>>
STORY HIGHLIGHTS
  • FBI, CIA criticized for not keeping better track of Tamerlan Tsarnaev before attack
  • Bruce Schneier: Connecting the dots seems easy in hindsight, but in real life, it's not
  • He says there are an enormous number of potential bad guys
  • Schneier: If a terrorist plot succeeds, it doesn't mean law enforcement systems failed

Editor's note: Bruce Schneier is a security technologist and author of "Liars and Outliers: Enabling the Trust Society Needs to Survive."

(CNN) -- The FBI and the CIA are being criticized for not keeping better track of Tamerlan Tsarnaev in the months before the Boston Marathon bombings. How could they have ignored such a dangerous person? How do we reform the intelligence community to ensure this kind of failure doesn't happen again?

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.

Bruce Schneier
Bruce Schneier

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.

Kahneman, a Nobel prize winner, wisely noted: "Actions that seemed prudent in foresight can look irresponsibly negligent in hindsight." Kahneman calls it "the illusion of understanding," explaining that the past is only so understandable because we have cast it as simple inevitable stories and leave out the rest.

Nassim Taleb, an expert on risk engineering, calls this tendency the "narrative fallacy." We humans are natural storytellers, and the world of stories is much more tidy, predictable and coherent than the real world.

Millions of people behave strangely enough to warrant the FBI's notice, and almost all of them are harmless. It is simply not possible to find every plot beforehand, especially when the perpetrators act alone and on impulse.

We have to accept that there always will be a risk of terrorism, and that when the occasional plot succeeds, it's not necessarily because our law enforcement systems have failed.

Follow @CNNOpinion on Twitter.

Join us at Facebook/CNNOpinion.

The opinions expressed in this commentary are solely those of Bruce Schneier.

ADVERTISEMENT
Part of complete coverage on
July 28, 2014 -- Updated 2245 GMT (0645 HKT)
LZ Granderson says the cyber-standing ovation given to Robyn Lawley, an Australian plus-size model who posted unretouched photos, shows how crazy Americans' notions of beauty have become
July 28, 2014 -- Updated 1156 GMT (1956 HKT)
A crisis like the Gaza conflict or the surge of immigrants can be an opportunity for a lame duck president, writes Julian Zelizer
July 26, 2014 -- Updated 1822 GMT (0222 HKT)
Carol Costello says the league's light punishment sent the message that it didn't consider domestic violence a serious offense
July 28, 2014 -- Updated 1251 GMT (2051 HKT)
Danny Cevallos says saggy pants aren't the kind of fashion statement protected by the First Amendment.
July 28, 2014 -- Updated 1852 GMT (0252 HKT)
Margaret Hoover says some GOP legislators support a state's right to allow same-sex marriage and the right of churches, synagogues and mosques not to perform the sacrament
July 28, 2014 -- Updated 1831 GMT (0231 HKT)
Megan McCracken and Jennifer Moreno say it's unacceptable for states to experiment with new execution procedures without full disclosure
July 28, 2014 -- Updated 1850 GMT (0250 HKT)
Priya Satia says today's drones for bombardment and surveillance have their roots in the deadly history of Western aerial control of the Middle East that began in World War One
July 28, 2014 -- Updated 1635 GMT (0035 HKT)
Jeff Yang says it's great to see the comics make an effort at diversifying the halls of justice
July 26, 2014 -- Updated 1555 GMT (2355 HKT)
Rick Francona says the reported artillery firing from Russian territory is a sign Vladimir Putin has escalated the Ukraine battle
July 27, 2014 -- Updated 1822 GMT (0222 HKT)
Paul Callan says the fact that appeals delay the death penalty doesn't make it an unconstitutional punishment, as one judge ruled
July 24, 2014 -- Updated 2225 GMT (0625 HKT)
Pilot Robert Mark says it's been tough for the airline industry after the plane crashes in Ukraine and Taiwan.
July 25, 2014 -- Updated 1510 GMT (2310 HKT)
Jennifer DeVoe laments efforts to end subsidies that allow working Americans to finally afford health insurance.
July 26, 2014 -- Updated 1533 GMT (2333 HKT)
Ruti Teitel says assigning a costly and humiliating "collective guilt" to Germany after WWI would end up teaching the global community hard lessons about who to blame for war crimes
July 25, 2014 -- Updated 1245 GMT (2045 HKT)
John Sutter responds to criticism of his column on the ethics of eating dog.
July 25, 2014 -- Updated 1302 GMT (2102 HKT)
Frida Ghitis says it's tempting to ignore North Korea's antics as bluster but the cruel regime is dangerous.
July 25, 2014 -- Updated 1850 GMT (0250 HKT)
To the question "Is Putin evil?" Alexander Motyl says he is evil enough for condemnation by people of good will.
July 24, 2014 -- Updated 1803 GMT (0203 HKT)
Laurie Garrett: Poor governance, ignorance, hysteria worsen the Ebola epidemic in Sierra Leone, Guinea, Liberia.
July 24, 2014 -- Updated 1349 GMT (2149 HKT)
Patrick Cronin and Kelley Sayler say the world is seeing nonstate groups such as Ukraine's rebels wielding more power to do harm than ever before
July 23, 2014 -- Updated 2205 GMT (0605 HKT)
Ukraine ambassador Olexander Motsyk places blame for the MH17 tragedy squarely at the door of Russia
July 24, 2014 -- Updated 1142 GMT (1942 HKT)
Mark Kramer says Russia and its proxies have a history of shooting down civilian aircraft, often with few repercussions
July 24, 2014 -- Updated 1853 GMT (0253 HKT)
Les Abend says, with rockets flying over Tel Aviv and missiles shooting down MH17 over Ukraine, a commercial pilot's pre-flight checklist just got much more complicated
July 24, 2014 -- Updated 1317 GMT (2117 HKT)
Mark Kramer says Russia and its proxies have a history of shooting down civilian aircraft, often with few repercussions
July 24, 2014 -- Updated 1637 GMT (0037 HKT)
Gerard Jacobs says grieving families and nations need the comfort of traditional rituals to honor the remains of loved ones, particularly in a mass disaster
July 24, 2014 -- Updated 1413 GMT (2213 HKT)
The idea is difficult to stomach, but John Sutter writes that eating dog is morally equivalent to eating pig, another intelligent animal. If Americans oppose it, they should question their own eating habits as well.
July 23, 2014 -- Updated 1630 GMT (0030 HKT)
Bill van Esveld says under the laws of war, civilians who do not join in the fight are always to be protected. An International Criminal Court could rule on whether Israeli airstrikes and Hamas rocketing are war crimes.
July 23, 2014 -- Updated 1408 GMT (2208 HKT)
Gordon Brown says the kidnapped Nigerian girls have been in captivity for 100 days, but the world has not forgotten them.
ADVERTISEMENT