TODAY | April 21, 2013
>>> the events of the past week in boston played out worldwide online. in most cases, a good thing. though as michelle franzen reports for some it came at a price. territory was a week like no other, starting with the bombing attack at the boston marathon .
>> something just blew up.
>> reporter: and followed by a massive manhunt for the suspects. one in which social media played a significant role, giving police solid leads.
>> it was a ride-along like we've never seen in any kind of american news story.
>> reporter: but also, experts say, fuelling a wildfire of misinformation and speculation.
>> the problem is, gossip is now like a computer virus . and in seconds it can spread around the planet.
>> reporter: in the days after the attack, police reached out to the public asking for cell phone photos and tips.
>> there has to be hundreds if not thousands of photographs or videos.
>> reporter: after reviewing surveillance cameras, authorities released video of two men with backpacks, soon photos began circulating on the internet leading to some mistakes.
>> bag men. feds seek these two pictured at boston marathon .
>> reporter: "the new york post" published a photo of two men who were not the suspects. one of the falsely accused spoke out.
>> i said i see my picture. i was like, what's the consequences? what are people going to say?
>> reporter: in the wild world of twitter, there was a trove of the good with collective cheers when boston police posted they had captured 19-year-old dzhokhar tsarnaev. the bad, fake websites and twitter accounts along with glimpses of real social media and internet activity by both suspects. and the ugly. images posted of tamerlan tsarnaev after he died, too graphic to show here, circulated across the internet. reminders, experts say, of the power social media can have in the moment and lessons we can use in the future.
>> i hope that as we move forward into the next crisis like this, people are going to learn the importance of waiting until you know what you are passing along has at least some part of the truth in it.
>> reporter: for "today," michelle franzen , nbc news, new york.