Social Media Faces Privacy ‘Paradox’ in Spotting Underage Users

Social media platforms under pressure to shield children from harmful content face a dilemma: figuring out how old their users are without violating their privacy.

Lawmakers and advocacy groups are urging the platforms to protect young users from content that might cause body image or other mental health issues, while also safeguarding their personal data. Such data protections depend in part on knowing the age of a social media user, even as kids under 13 are said to lie to join platforms like Meta Platform Inc.’s Instagram and ByteDance Ltd.’s TikTok.

Privacy advocates worry that efforts to determine ...