When users upload photos on Facebook, faces and objects can be tagged to mark people in a photo. This feature is automatically enabled and Facebook has been challenged over the decision as privacy concerns are raised again.

Specifically, Senator Al Franken, chairman of the Judiciary Committee's Subcommittee on Privacy, Technology, and the Law, asked about the tag options being set as default with users having the option to turn it off.

Franken also criticized the social network for requiring users to click six times before the words "facial recognition" can be found and not clearly explaining how information is used. "Facebook could still do more," he said.

Tagging has been offline for weeks as Facebook performs maintenance. Rob Sherman, manager of privacy at Facebook, said the functionality would resume "soon." The maintenance has been due to "widespread" usage of the feature, according to website CIO.

"We think that's an appropriate choice because Facebook itself is an opt-in experience. People choose to be on Facebook because they want to share with each other," Sherman said to the committee on enabling tagging by default. Facebook users can configure tags to be approved before appearing, but the option isn't enabled by default and probably not known by a majority of users.

Franken talked about laws to clarify Facebook's facial recognition technology, admitting current laws are "almost totally unprepared" for such technology.

Tagging could become a bigger issue as Facebook aims to lower its barrier-to-entry age to just 13, despite the site originally being designed for college students. Senator Richard Blumethal suggested tagging should be disabled by default for 13-year-old teenagers.

"It's something certainly that we would considering actively, but until we make a decision about changing our policy I think it's premature to say exactly how we would implement it," Sherman added. It's possible to argue children shouldn't be allowed on a social network with around 800 million users - and growing, probably - but if 13-years-olds are on Facebook, then it would make sense to present a feature limited version of the service.

Blumenthal asked Facebook to not collect or store data for the younger age group. It remains to be seen if Facebook follows through with the decision.

Allowing 13-year-old children onto a social network seems like a grey area, especially considering Facebook's size, and it's not an idea parents may be comfortable with. Talking to age groups who are older by a year or two isn't a 13-year-olds normal environment. Regarding tagging, Facebook certainly has to create a greater awareness of its features.

Google Plus recently topped Facebook in terms of customer satisfaction, as consumers disliked new features including Timeline.