Facebook is considering incorporating most of its 1 billion-plus members' profile photos into its growing facial recognition database, expanding the scope of the social network's controversial technology.
Facebook revealed the possible move in an update to its data use policy Thursday, saying it is intended to improve the performance of the Tag Suggest feature. The feature uses facial recognition technology to speed the process of labeling friends and acquaintances who appear in photos posted on the network.
The technology currently automatically identifies faces in newly uploaded photos by comparing them only to previous snapshots in which users were tagged. Users can choose to remove tags identifying them in photos posted by others.
The changes would come as Facebook and other Internet companies' privacy practices are under scrutiny after revelations of the government's electronic surveillance program.
(Read more: Facebook: Governments demand data on 38K users)
Facebook, Google and other companies have insisted that they have never participated in any program giving the government direct access to their servers, and that they provide information only in response to specific requests after careful review and as required by law.
Facebook Chief Privacy Officer Erin Egan said that adding members' public profile photos would give users better control over their personal information by making it easier to identify posted photos in which they appear.
"Our goal is to facilitate tagging so that people know when there are photos of them on our service," Egan said.
She stressed that Facebook users uncomfortable with facial recognition technology will still be able to "opt out" of the Tag Suggest feature altogether, in which case the person's public profile photo would not be included in the facial recognition database.
Facial recognition has been a sensitive issue for technology companies and has raised questions among some privacy advocates and government officials. Tag Suggest, which the company introduced in 2011, is not available in Europe because of concerns brought up by regulators there.
Google also employs similar technology, but requires user consent. And it has banned third-party software makers from using facial recognition technology in apps designed for its Glass wearable computer.
Egan said that though Facebook is not using facial recognition technology for any other features, that could change.
(Related video: NSA data was not misused: US Rep.)
"Can I say that we will never use facial recognition technology for any other purposes? Absolutely not," Egan said. But, she added, "if we decided to use it in different ways, we will continue to provide people transparency about that, and we will continue to provide control."
Facebook also amended its Statement of Rights and Responsibilities on Thursday so that members under 18 are deemed to have affirmed that a parent or legal guardian has agreed to allow marketers to use some of their personal information in ads.
The amended language was the result of a recent court-approved legal settlement regarding its "sponsored stories" ads.