Lesley Stahl: In order for this to work, does the person you're trying to identify have to be on one of these social networks?
Alessandro Acquisti: You must have, somewhere on the Internet, a face with your name on it.
Lesley Stahl: Well, let's say someone doesn't have a Facebook account, but his or her daughter or son does, and they've got your picture. So are they now automatically in the mix?
Alessandro Acquisti: It's funny because one of the participants, before doing the experiment, told us, "You're not going to find me because I'm very careful about my photos online." And we found him. Because someone else had uploaded a photo of him.
But if an academic can easily mine our data with facial recognition, what about the government? Well, the government has a problem because to be effective, facial recognition requires a good database. Facebook for instance has one with billions and billions of photos. The government not nearly that many, and so the FBI is now assembling on these rows of servers the largest biometric database on Earth, costing over a billion dollars. Showing the system for the first time publicly, FBI Assistant Director David Cuthbertson demonstrated how police detectives might use it, when it's fully up and running next year.
David Cuthbertson: This would be the person-- the photograph of the person they are trying to identify.
He used a picture of a deceased criminal.
David Cuthbertson: And so we're submitting the photograph into the system. And it's looking through 12.8 million mug shots in the current system. The FBI has been collecting photographs along with arrest fingerprints for a number of years. This is the first time that anyone's been able to search against those using facial recognition technology.
You've seen this on cop shows, but actually it hasn't been possible to do on a national scale in real time until now.
Lesley Stahl: Will you have a picture of every single American?
David Cuthbertson: No. Absolutely not. Just people who've been arrested.
But why doesn't the FBI just download pictures from Facebook or LinkedIn, since there's no law saying they can't.
David Cuthbertson: There's maybe no legal barrier, but no legal authorization.
Lesley Stahl: You couldn't just do it 'cause you wanted to?
David Cuthbertson: No, ma'am. I would have lawyers lining up outside my door.
Lesley Stahl: So why are so many privacy experts up in arms over what you're doing if you're so restricted by rules and regulations and codes?
David Cuthbertson: I think we get lumped into other factors, other uses of facial recognition whether they be commercial, social media. We're all kind of in this thing together.
You can't forget that it begins with all the information we feed so freely and perpetually onto the Internet: "likes," purchases, searches, not to mention our faces.
Alessandro Acquisti: Often we are not even aware of how much data we are actually revealing or it is being gathered about us or, in fact, how it would be used. The idea that you can start from a face and predict social security numbers from that face seemed quite alien and surprising. But now we know that it can be done.
Lesley Stahl: So there's no place to hide, absolutely no place to hide.
Alessandro Acquisti: It's those places are shrinking.