Face-Matching by means of Facebook Profiles

LAS VEGAS--Facebook's online privacy woe are famous. But here's an offline one: its massive database of profile photos can be used to recognize you as you're walking down the street.

A Carnegie Mellon University investigator today explained how he pull together a database of about 25,000 photographs taken from students' Facebook profiles. Then he set up a desk in one of the university grounds buildings and asked willing volunteers to peer into Webcams.

The results: facial recognition software put a name to the face of 31 percent of the students after, on average, less than three seconds of rapid-fire comparisons.

In a not many years, "facial visual searches may become as ordinary as today's text-based searches," says Alessandro Acquisti, who presented his work in collaboration with Ralph Gross and Fred Stutzman at the Black Hat computer security conference here.

because a evidence of idea, the Carnegie Mellon researchers also developed an iPhone app that can take a photograph of someone, tube it through facial acknowledgment software, and then display on-screen that person's name and fundamental figures.

This has "ominous risks for privacy" says Acquisti, an connect professor of information technology and public policy at the Heinz College at Carnegie Mellon University. Widespread facial recognition tied to databases with real names will erode the sense of mystery that we imagine in public, he said.

a different check compared 277,978 Facebook profiles next to nearly 6,000 profiles extracted from an unnamed dating Web site

About 1 in 10 of the dating site's members--nearly all of whom used pseudonyms--turned out to be individual.

Facebook isn't the only source of profile data, of course. LinkedIn or Google+ might work. But because of its vast database and its wide-open profile photos, Facebook was the obvious choice. (Facebook's privacy policy says: "Your name and profile picture do not have solitude settings.")

Facial recognition technology, which has been developing in labs for decades, is finally going mainstream. Face.com opened its doors to developers last year; the technology is built into Apple's Aperture software and Flickr. Google bought a face-recognition technology in the last few weeks, and Facebook's automated photo-tagging has drawn privacy scrutiny.

In the hands of law enforcement, however, face recognition can raise novel civil liberties concerns. If university researchers can assemble such an extensive database with just Facebook, police agencies or their contractors could do far more with DMV or passport photographs--something that the FBI has been doing for years. (The U.S. Army partially funded the Carnegie Mellon research.)

set free is the first to admit that the technology isn't ideal. It works best with frontal face photos, not ones taken at an angle. The larger the database becomes, the more time comparisons take, and the more false-positive errors happen.