DAVID GREENE, HOST:
The New York Post last week ran a front-page photo of two teenage runners under the headline "Bag Men," implying that they had something to do with the Boston Marathon backpack bombs. Turns out those kids had nothing to do with the attacks.
But As NPR's Steve Henn reports, they came to the public's attention after their images were scooped up and pored over by hundreds of online, amateur sleuths.
STEVE HENN, BYLINE: Alex Madrigal covers technology at The Atlantic. [POST-BROADCAST CLARIFICATION: The first name of The Atlantic writer is Alexis, not Alex.] And he was watching the social media site Reddit last week, as some of its users decided to get involved in the aftermath of the Boston attack.
ALEXIS MADRIGAL: People at - not just at Reddit, but at Fortune and other Internet forums decided that they could help with the investigation by taking all the photos that had come out of the bombing, combing through them, and looking for - I'm sort of air-quoting here - "suspicious characters"; people carrying backpacks, people who might look like a terrorist.
HENN: Even in the beginning, Madrigal compared what was going on to vigilantism.
MADRIGAL: It was actually disrupting the official investigation because they were having to deal with all of these - sort of false suspects getting floated - and people getting accused. And it just turned into a big, old mess - which I think was quite predictable.
HENN: In fact, one reason investigators released photos of the suspects last week was to tamp down on rumors. Unfortunately...
MADRIGAL: People started to develop this theory that Sunil Tripathi was one of the bombers.
HENN: Tripathi is a 22-year-old student at Brown University, who's been missing since mid-March. The rumor was baseless, but it spread.
SANGEETA TRIPATHI: Buzz continued to build and build.
HENN: Sangeeta Tripathi is Sunil's sister. She and her family have been searching for her brother for more than a month. Early on, they set up a Facebook page.
TRIPATHI: In the hopes that one day somewhere - you know, Suni might log on in a public library, if he's OK; see the notes, and be triggered to reach out and call home.
HENN: But Thursday night, that Facebook page began to attract hateful, angry posts. Shortly after 10, the family pulled it down. By 11 p.m., Boston police were closing in on the true suspects in the case. And Alexis Madgrigal says the Internet was listening.
(SOUNDBITE OF POLICE RADIO CALL)
UNIDENTIFIED DISPATCHER: Ten-four. All units, 1-8-9 mapped out, should be advised...
MADRIGAL: There were people who during this time, were taking this stuff off the police scanner, and writing it down on Reddit.
HENN: Around 3 a.m., tweets and posts went up online, saying Sunil Tripathi had been named by police as a suspect - on the scanner. Again, this wasn't true; there's no record of police mentioning his name. But Sangeeta Tripathi says those tweets created a circus.
TRIPATHI: I personally got over 58 calls from media, between 3 a.m. and 4:11 in the morning. You know, my parents, who are very, very - raggedy from the past 36 days of our lives, were getting called and emailed.
HENN: News trucks showed up at their home. Sangeeta Tripathi says her family was already sick with worry - fearful for Sunil's safety, and his state of mind.
TRIPATHI: Sunil - clearly, to leave your whole family and your life, one is not in a good place, when one does that; and we are very, very worried about the costs of rash actions on fragile human beings. We hope that this doesn't happen again, to somebody else.
HENN: In three hours, that media siege was over. Police released the names of the real suspects. Today, the Tripathi family is still searching for Sunil. And yesterday, the general manager of Reddit apologized.
Steve Henn, NPR News, Silicon Valley.