Consumer advocates and child advocacy groups are asking a federal appeals court to overturn a legal settlement that Facebook negotiated in a class-action lawsuit over the social network's practice of using members' names and photos in advertisements.

The settlement was approved last year by a federal judge, but attorney Scott Michelman of the watchdog group Public Citizen said the terms violate child-protection laws of at least seven states, including California, because the agreement doesn't require Facebook to get parents' consent before using minors' names or photos in so-called "social" ads.

That puts "the most naive, youngest subgroup of Facebook users at the mercy of a pretty large and sophisticated advertising machine," added Hudson Kingston of the Center for Digital Democracy, based in Washington, D.C.

At stake is a form of advertising that's been highly profitable for the social network: When a user clicks on the Facebook "like" button for a post or page that's promoted by an advertiser, Facebook sometimes adds that endorsement -- and includes the user's name and photo -- when it shows the ad to other users.

Facebook hasn't halted that practice, but it agreed last year to modify its terms of service to explicitly warn users that, by joining the social network, they were giving consent to have their names and photos used in ads. Facebook also agreed to create a system for parents to withdraw consent on behalf of their children.

A spokeswoman for the company said Thursday that the settlement "provides substantial benefits to everyone on Facebook, including teens and their parents, and goes beyond what any other company has done to provide consumers visibility into and control over their information in advertising."

But critics say the system unfairly puts the burden on children and their parents who may not be aware of Facebook's policies. The company's terms of service include a sentence telling minors that, by using the service, they are indicating that their parents have agreed to the ads.

"That kind of consent is just as invisible as the initial practice," said Margaret Becker, the mother of a 15-year-old girl who is participating in the legal appeal filed with the 9th U.S. Circuit Court of Appeals in San Francisco.

Many teens are unlikely to read or understand the implications of Facebook's formal policies, according to consumer advocates who filed the appeal. Becker said her daughter clicked the "like" button for a favorite band and was surprised to later see her photo in an advertisement for the band.

"Kids joke with each other" and believe their friends will understand what they mean, Becker added. "But when you take it out of that context and blast it out as an advertisement, that not only exponentially expands the scope of the child's action but it can totally distort what the child's intent was."

Opponents noted that Google has said it won't use minors in social advertising on its services. Critics said Facebook should adopt a similar policy or be required to get parents' consent before using minors in ads.

Facebook spokeswoman Jodi Seth noted that U.S. District Judge Richard Seeborg rejected similar legal arguments by the opponents when he approved the settlement in a lower federal court last year.

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