Facebook founder and CEO Mark Zuckerberg speaks at the TechCrunch Disrupt SF 2012 conference on September 11, 2012 in San Francisco.(KIMIHIRO HOSHINO/AFP/GettyImages)

When Mark Zuckerberg spoke yesterday in San Francisco at the much-anticipated technology conference TechCrunch Disrupt, he declared Facebook “mission-driven” with an astounding ability to make the world “more open and connected.”

What he didn’t know was that earlier that day, Facebook had served as a vital tool for New York City police officers in the arrest of 49 members of Rockstarz and the Very Crispy Gangsters—two Brooklyn-based gangs who patrol the streets of East New York.

Police Commissioner Raymond Kelly announced that the NYPD had been tracking members of the gangs on Facebook by using false aliases and special laptops whose internet activity cannot be traced. Members of the gangs generated suspicious cross-gang friend requests, and posted provocative pictures of each other’s homes, replete with threatening captions. One gang member even posted a picture of himself in the belt and watch of a recently murdered member of the opposing gang.

The 49 men, most of whom are around twenty years old, were arrested on charges of murder, attempted murder, and conspiracy. Their gang activity has resulted in ten shootings over the past three years, resulting in the deaths of members of both gangs as well as innocent bystanders.

The police have chosen to keep their methods of Facebook-stalking under wraps.

Zuckerberg’s Upbeat Remarks Send Stocks Soaring [Time]
NYPD Social Media Guidelines [NYM]
Brooklyn Gangs Boasted of Murders on Facebook [NYT]