Sunil Tripathi went missing in March 2013. (Image courtesy of the family)

On Thursday, April 18th, three days after the Boston Marathon bombings, the FBI released photos of two suspects.

Very early Friday morning, on the website Reddit, someone posted side-by-side photos of the second suspect and Sunil Tripathi, a 22-year-old Brown University student who had been missing since March 16.

This image from video released Thursday, April 19, 2013 by the FBI shows the second suspect sought in connection with the Boston bombings. (FBI via AP)

Reddit users speculated that Tripathi might be the younger bomber.

Within hours, a Twitter user named Greg Hughes shifted speculation to presumed fact, when he said he heard the name Sunil Tripathi on a Boston Police scanner. It turns out that was also not true.

The rumor went from there to a Connecticut news anchor and on and on.

That single, incorrect Reddit posting ricocheted around the Internet, shattering Tripathi's family and calling into question, again, the role of social media.

Tripathi's body was found on April 23, after the actual bombing suspects had been officially identified and apprehended.

Suspect number two was Dzhokhar "Jahar" Tsarnaev. His older brother Tamerlan Tsarnaev was suspect number one.

Jay Caspian Kang traced the anatomy of the rumor in a recent New York Times Magazine piece, "Should Reddit Be Blamed for the Spreading of a Smear?" He joins us.