A week before opening fire on an Orlando nightclub, Omar Mateen was on Facebook. Perhaps he was looking for inspiration: According to the chairman of the Senate Homeland Security Committee, Mateen searched the site for a speech by Abu Bakr al-Baghdadi, the secretive ISIS leader. On the day of the shooting, he allegedly pledged allegiance to al-Baghdadi in a Facebook post.
Once dependent on leaflets and videotapes, terrorist groups now use social media as a chief recruiting tool. Facebook, Twitter, and other social networks have responded by accelerating campaigns to shut down accounts that spew pro-ISIS messages on their platforms; Twitter in particular has seen some success suspending ISIS-affiliated accounts by expanding its teams that watch for objectionable content. But it’s impossible to keep terrorist propaganda off of social networking platforms entirely.
Each day, Twitter users tweet an average of 500 million times and more than a billion people log into Facebook.
Instead of relying on humans to finger dangerous content, a computer-science professor at Dartmouth is proposing a system that proactively flags extremist photos, videos, and audio clips as they’re being posted online. But the software has been met with reluctance from the very social media companies that would use it, even before it was announced last week.
The project’s leader is Hany Farid, the chair of Dartmouth’s computer-science department. Farid’s was the mind behind PhotoDNA, a Microsoft-backed system that detects child pornography as it’s posted online. That service relies on a stock of millions of pornographic images of children collected and maintained by the National Center for Missing and Exploited Children, or NCMEC. PhotoDNA creates a unique fingerprint of each image called a hash, which can identify the photo even if it’s been manipulated or cropped. It’s used by a long list of major organizations and companies—from social networks and cloud-storage services to governments and law enforcement agencies—to prevent images of juvenile sexual abuse from spreading. Microsoft has made the service free and easy for any new online services to deploy.
When the service was introduced in 2008, Farid says, the bulk of the child pornography traded on the internet was in the form of images—but today, child porn is largely in video form. To catch up, Farid has spent the last eight months updating PhotoDNA to be able to flag video and audio files as well as images.
The expanded fingerprinting technology can help broaden the fight to suppress child pornography online—but Farid has long hoped to use it to attack another genre of offensive content, Atlantic reported.
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