IN RE: SOCIAL MEDIA ADOLESCENT ADDICTION/PERSONAL INJURY PRODUCTS LIABILITY LITIGATION
Issue
In *In re: Social Media Adolescent Addiction/Personal Injury Products Liability Litigation*, Meta Platforms argues that five witnesses it designated for trial were properly and timely disclosed under the court's pretrial orders, and that the State Attorneys General lack grounds to strike them from Meta's trial witness list. The dispute turns on whether Meta's disclosures complied with applicable scheduling requirements and, if not, whether any deficiency was substantially justified under Fed. R. Civ. P. 37(c)(1). Meta further argues that the AGs' supplemental filing in support of their motion to strike was itself procedurally improper, having been filed without leave of court in violation of local rules governing motion practice.
What Happened
Filed on June 4, 2026, by defense counsel Ashley M. Simonsen, this is a procedural notice submitted by Meta in the pretrial phase of MDL No. 3047 in the Northern District of California. The filing attaches twenty exhibits (Exhibits A–T) and a supporting declaration by Ms. Simonsen, submitted to complete the evidentiary record in support of Meta's earlier opposition (ECF 3060-1) to the State AGs' motion to strike five named witnesses from Meta's trial witness list (ECF 3056). Meta argues that the AGs' subsequent supplemental filing (ECF 3104) was filed without court authorization and asks the court to strike it as procedurally defective. The exhibits appear to include correspondence and disclosure records bearing on the timeliness and propriety of Meta's witness designations, though the full content of those materials was not available for independent review.
Why It Matters
This filing does not advance any substantive legal doctrine — it is pretrial housekeeping in one of the most consequential social media liability cases currently pending in federal court. Its practical stakes are nonetheless real: if Meta's five challenged witnesses survive the motion to strike, they will be available at trial to contest causation, damages, or platform-design claims before the jury in the State AG bellwether proceeding. How Judge Gonzalez Rogers resolves the dispute over the AGs' supplemental filing may also offer a signal about how strictly motion practice discipline will be enforced as this MDL moves into its trial phase. For those tracking the litigation, the document is less a source of new legal rules than an indicator of where the parties are expending effort in the final stretch before trial.
Related Filings
Other proceedings in the same litigation tracked by this monitor.
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