Facebook Adopts Microsoft’s PhotoDNA

CYBERSPACE—Less than a week after Florida police arrested a man who had placed 36 images of child sexual abuse on a Facebook page under an alias he had created, the massive social network has announced that it has started using PhotoDNA, the hash-based technology created by Microsoft and donated to the National Center for Missing and Exploited Children (NCMEC) in 2009.

According to The New York Times, Facebook “has begun to use PhotoDNA to hunt for several thousand registered illegal images among the 200 million images uploaded by its users each day.”

Ernie Allen, chief executive of NCMEC said he hopes Facebook is the first of many companies to use the technology, which “can currently search for about 10,000 images collected by [NCMEC], which has amassed 48 million images and videos depicting child exploitation since 2002, including 13 million in 2010 alone,” reported the Times. PhotoDNA can identify such contraband even if the image has been cropped or otherwise altered.

Facebook, Microsoft and NCMEC are hosting an online presentation about the technology Friday from 3-6 p.m. ET.  More information about the event can be found here.

“We’re very passionate about PhotoDNA because we’ve seen it work,” said Microsoft general counsel Brad Smith. “We invented it through Microsoft research, and we are trying to give it away free, including to our competitors.”

According to Allen, NCMEC is using PhotoDNA to find and remove only known images of the sexual exploitation of pre-pubescent children, meaning those 13 and under. All sexual imagery of minors under the age of 18 is illegal to make and possess, but Allen said the decision to narrow the focus was made in order to not trample “on the privacy and free-speech rights of consumers of adult pornography,” the Times reported. 

Calling the initiative to get as many institutions to use PhotoDNA as possible a battle against the “worst of the worst” images of child sexual abuse, Allen added, “These are crime scene photos. This tool is essential to protect these victims and to prevent, to the greatest degree possible, the redistribution of their sexual abuse.”

The rollout of PhotoDNA comes after an intensive year of testing of the technology by Microsoft on its SkyDrive, Windows Live and Bing services, the results of which, according to the Times, indicated “a chillingly large trade in these images. A network that compares 10 million images to the center’s inventory of 10,000 illegal photos can expect to have about 125 hits a day, according to Hany Farid, a Dartmouth computer science professor and expert in digital imagery who worked with Microsoft to hone the technology. At least 50,000 child pornography images are being transmitted online every day, he estimated.” The paper added that a future use of PhotoDNA could include identifying images online for the purpose of protecting them from intellectual property theives.

A special Microsoft page devoted to PhotoDNA can be found here