SAN FRANCISCO/LONDON Facebook is providing European regulators with information about its use of facial recognition technology, in response to concerns about the company's roll-out of the technology's availability outside of the United States.
Facebook, the world's No. 1 Internet social network, said there was no "formal investigation" under way.
"We have noted the comments from some regulators about this product feature and we are providing them with additional information which we are confident will satisfy any concerns they will have," Facebook spokeswoman Sophy Tobias told Reuters in an email on Wednesday.
The move comes after comments by Gerard Lommel, a Luxembourg member of the so-called Article 29 Data Protection Working Party, who said the group would study Facebook's use of facial recognition technology for possible rules violations, according to a report in Bloomberg earlier on Wednesday.
The Data Protection Working Party, a group of 27 national data protection and privacy agencies that advises the European Commission on privacy issues, could not immediately be reached for comment.
On Tuesday, Facebook said it had expanded the availability of its "Tag Suggestions" product, which uses facial recognition technology to automatically identify the people who appear in certain photos posed on Facebook.
Facebook, which announced in December that it planned to introduce the service in the United States, said on Tuesday that the feature was in fact now available in "most countries" and acknowledged that it should have been "more clear with people during the roll-out process when this became available to them."
The lack of notification about the wider roll-out of the new technology and the fact that Facebook has automatically enabled the technology in users' settings have raised concerns among some privacy advocates, who say it should be up to users to switch it on.
While facial recognition technology is used in other photo products such as Apple Inc's iPhoto and Google Inc's Picasa, Facebook's use of the technology across its social network of more than 500 million users could raise novel privacy issues, according to Marc Rotenberg, president of the privacy-advocacy group Electronic Privacy Information Centre.
The Facebook product scans users' newly uploaded photos, comparing the faces in the photos against previously labelled photos to see if it can match any of the people. If a match is found, Facebook alerts the person uploading the photos and invites them to "tag," or identify, the person in the photo.
Facebook said the product helps speed up the process of identifying and labelling people in photos, a popular practice among Facebook users that the company said currently occurs more than 100 million times a day.
Facebook has stressed that the automated photo-tagging suggestions are only made when new photos are added to Facebook, that only friends are suggested and that users can disable the feature in their privacy settings.
(Additional reporting by Foo Yun Chee; Editing by Steve Orlofsky)