In re Social Media Adolescent Addiction/Personal Injury Products Liability Litigation
U.S. District Court, Northern District of California · N.D. Cal. · California bar guidance
Verified April 26, 2026
- Citation
- In re Social Media Adolescent Addiction/Personal Injury Prods. Liab. Litig., No. 4:22-md-03047-YGR, Dkt. 2750 (N.D. Cal. Feb. 17, 2026)
- Decided
- February 17, 2026
Summary
Plaintiffs' school district expert Brian Osborne, Ed.D., a former superintendent retained in the social media MDL before Judge Yvonne Gonzalez Rogers, conceded at deposition that certain academic articles he relied upon did not exist and that other citations were miscites generated by an AI citation tool. Defendants Meta, Google, ByteDance, and Snapchat sought to exclude Osborne's opinions on this and other grounds. Plaintiffs responded that the underlying articles were real and only the citation formatting had been incorrectly produced by the AI tool, then corrected.
- AI tool:
- Unspecified generative AI
What sanction did the court impose?
The court denied the Rule 702 motion to exclude Osborne's testimony, including on the AI-citation ground, and held that defendants may raise the issue on cross-examination. No monetary sanction was imposed and no separate Rule 11 proceeding was initiated against counsel; the AI hallucination issue was preserved as a credibility matter for trial rather than treated as a sanctionable filing defect.
Why does In re Social Media Adolescent Addiction/Personal Injury Products Liability Litigation matter for law firms using AI?
This order is notable because the AI hallucination came from a retained expert rather than counsel, and the court treated it as a matter of weight for cross-examination rather than admissibility or sanctions. For managing partners overseeing expert engagements in high-stakes litigation, the order underscores that AI-citation discipline now extends past the lawyers signing the brief to every consulting and testifying expert whose report the firm submits, and that opposing counsel will mine deposition transcripts for fabricated citations as an impeachment vector.
Sources
Primary sources
Further reading
Source PDF is a Westlaw printout mirrored from the Damien Charlotin hallucination database. We are working to add the underlying court docket (PACER, CourtListener, or court website) as a second source.