WASHINGTON - Sen. Al Franken tagged Facebook Wednesday, but not in the way the world's largest social network is used to. The Minnesota Democrat called out the company for making it hard for members to avoid having online photos of themselves shared with people they might not want to see them.

Chairing a hearing of a subcommittee on privacy and technology, Franken challenged Facebook's practice of automatically including its members in a facial recognition program for photographs.

Facebook's manager of privacy and public policy, Rob Sherman, told Franken that "Facebook is an opt-in experience," but he said the network made it easy for users to stop photo tracking if they wanted.

Franken replied that it took "six clicks" on Facebook's "easy-to-use privacy settings" for a user to even find the words "photo recognition." In contrast, the senator added, Google leaves facial recognition software off until users ask to turn it on.

At issue in the exchange was the right of individuals to control the distribution of their images and identities. Facial recognition technology has improved in the past decade to the point where so-called "face prints" are on the verge of overtaking fingerprints as the most valuable identification tool for law enforcement.

At the same time, the collection of face prints leaves innocent people vulnerable to abuse.

At its best, facial recognition technology can catch criminals, privacy expert Alessandro Acquisti explained to the packed hearing room. At its worst, "it can tell a stalker in a bar where you live."

Wednesday's hearing raised issues ranging from public safety to a culture that increasingly relies on Internet connections to function.

"Facebook," Duke law professor Nita Farahany told Franken, "is changing our expectations of privacy."

Jim Spencer • 202-383-6123