Knowing Where to Focus the Wisdom of Crowds

It looks as if the theory of the “wisdom of crowds” doesn’t apply to terrorist manhunts.

Last week after the Boston Marathon bombings, the Internet quickly offered to help find the people responsible. In a scene metaphorically reminiscent of a movie in which vigilantes swarm the streets with pitchforks and lanterns, people took to Reddit, the popular community and social news Web site, and started scouring images posted online from the bombings.

One Reddit forum told users to search for ”people carrying black bags,” and noted that “if they look suspicious, then post them. Then people will try and follow their movements using all the images.”

In the process, each time a scrap of information was discovered â€" the color of a hat, the type of straps on a backpack, the weighted droop of a bag â€" it was passed out on Twitter like “Wanted” posters tacked to lampposts. It didn’t matter whether it was right, wrong or even completely made up (some images posted to forums had been manipulated) â€" off it went, fiction and fact indistinguishable.

Some misinformation online landed on the front page of The New York Post, incorrectly identifying an innocent high school student as a suspect.

Later in the week, the Web wrongly identified one of the suspects as  a student from Brown University who went missing earlier this month. As Alexis Madrigal of The Atlantic noted in a lengthy study trying to understand how the student was named a suspect by the public and not by the police, the information appears to have been plucked out of thin cyber air. “Perhaps this is some kind of hoax perpetrated by some unknown group,” he wrote.

Although the real suspects were eventually identified, investigators have now come out to say that these online crowds were doing more damage than good in their quest to help.

On Sunday The Washington Post offered a detailed account of how investigators found the suspects, with thousands of local and federal officials engaging in a “painstaking and mind-numbing” search through videos and photos from the area. But in addition to combing through a million needles in a million haystacks, the Boston police commissioner, Edward Davis, told the paper that the authorities partly released images of the real suspects to try to control the flood of misinformation flowing onto social media sites where “online vigilante detectives” might have tarnished the investigation.

Perhaps the scariest aspect of these crowd-like investigations is that when information is incorrect, no one is held responsible.

As my colleague David Carr noted in his column this week, “even good reporters with good sources can end up with stories that go bad.” But the difference between CNN, The Associated Press or The New York Post getting it wrong, is that those names are held accountable when they publish incorrect news. No one is going to remember, or punish, the users on Reddit or Twitter who incorrectly identify random high school runners and missing college students as terrorists.

There is one area where the online crowd can help in a situation like this. When the correct information is released by the trained authorities, like the Boston Police Department and the Federal Bureau of Investigation, people can do their best to ensure that it is circulated through the crowd and seen by as many people as possible. There’s definitely wisdom in doing that.