Senator questions Facebook exec about facial-recognition feature Sen. Al Franken grilled a Facebook Inc. executive on the company's facial-recognition technology, urging the giant social network to be more upfront about how it is creating "face prints" of its users. Franken, a Minnesota Democrat, said it takes six clicks to reach a page on Facebook that explicitly says that the company is using facial-recognition technology. He held up placards with text from the site at a hearing of the Senate Judiciary Subcommittee on Privacy, Technology and the Law, which he chairs. "I'm worried about how Facebook handles the choices that it does give its users about this technology," he said. When a user uploads a photo, Facebook scans the faces in it to see if it can find any of that user's friends and suggests tagging them in the picture, although the feature is currently disabled for an update. Facebook beefed up its face-detection abilities in June when it acquired the Israeli firm Face.com, which provides recognition software for phone apps. As facial recognition becomes available on mobile phones, it could become increasingly difficult to remain anonymous in a crowd either online or offline. Publicly available tools can pull data from Facebook and match it up to other information, including addresses and in some cases Social Security numbers. Getting a match still depends on the quality of the photo and having a large database of images to compare with, but the technology is improving rapidly. The Electronic Privacy Information Center estimated that Facebook has 60 billion photographs of people, the largest collection in the world. Facebook users have to opt out of having their name suggested to friends for tagging. We think that's the appropriate choice because Facebook itself is an opt-in experience. People choose to be on Facebook because they want to share with one another," said Rob Sherman, the social network's manager of privacy and public policy. Because the tagging suggestions are based on friend relationships, he added, "we're not actually exposing any additional information as part of this process." My basic philosophy is that people have a right to privacy. It's a fundamental right," Franken said after the hearing. They have a right to know what is being taken, stored and how it's being used. I'm not so sure that when you are not opting in that you're really aware of what you're not agreeing to. You're not really agreeing to anything. Privacy advocates also worried at the time Facebook acquired Face.com that the vast database of photographs of faces could be a gold mine for law enforcement, which could seek to gain access to it to boost its own efforts to track people down. An FBI facial-recognition pilot project uses images from a mug shot database. Franken pressed Facebook on whether it would share its data with law enforcement agencies or other third parties. Sherman would not commit to saying Facebook would never turn over information but said any changes in its policies would be subject to a "robust" process. Alessandro Acquisti, a researcher at Carnegie Mellon University, suggested last year that widespread availability of facial-recognition technology could fundamentally change the nature of privacy and anonymity. His team was able to identify 1 in 3 students it photographed on a college campus. For some of those, the team was also able to predict Social Security numbers and discover other sensitive information. "Your phone will tell you the name of that person at the party whose name you always forget," Acquisti told the committee. Or it will tell the stalker in the bar the address where you live.