A high-stakes courtroom drama paused unexpectedly Tuesday when the social media addiction trial delayed proceedings after a juror was hospitalized with an illness — just one day before Mark Zuckerberg is scheduled to take the stand.

Los Angeles Superior Court Judge Carolyn B. Kuhl informed attorneys that one of the jurors had been admitted to the hospital but had not asked to be excused from service. After brief arguments, lawyers for the plaintiff, Meta Platforms and Google LLC agreed to grant the juror a day to recover.

“We will absolutely go forward tomorrow,” Judge Kuhl told the seated jurors after apologizing for the interruption.

A Trial Already Tested by Setbacks

The delay marks another disruption in what has become a closely watched bellwether trial — the first of at least nine planned from thousands of consolidated claims alleging social media companies harmed young users’ mental health.

Earlier this month, jury selection stalled for several days when Meta attorney Paul W. Schmidt of Covington & Burling LLP suffered a head injury. Schmidt later returned to court sporting a visible bump and black eye, joking to jurors that he had simply grown dizzy getting out of bed and struck his head.

Even logistics have intervened. Jury selection had to be relocated from the Spring Street Courthouse to another building blocks away after a water leak forced a temporary move.

The latest pause comes as the plaintiff’s team, led by W. Mark Lanier of The Lanier Law Firm, said their case is moving on schedule — possibly even ahead of it. Lanier told the court the hospitalized juror had been “taking extensive notes” and appeared deeply engaged.

“He did not ask to be excused,” Lanier said, adding that he worries jurors might drop off after Zuckerberg’s appearance, quipping that some could think, “We got to see the show, now we can go home and write a book.”

The court has seated 12 jurors and six alternates. If the ill juror cannot return Wednesday, an alternate will step in.

“An Empty Vessel” in a Polarized Case

During voir dire, many prospective jurors voiced strong opinions about the tech giants and Zuckerberg himself. The hospitalized juror — a retired film industry camera operator — stood apart.

“I’m an empty vessel,” he said at the time, drawing laughter in a courtroom otherwise heavy with tension.

Claims of Addictive Design

The bellwether trial centers on allegations that social media platforms deliberately engineered features to foster compulsive use among young people. Companies behind TikTok, Snapchat, YouTube and Instagram are accused of deploying mechanisms such as infinite scroll, autoplay, push notifications and digital reward systems to hook users.

Pretrial rulings from Judge Kuhl narrowed the scope of the litigation. The focus now rests on whether platform design features are inherently addictive — not on the third-party content posted by users. The companies face failure-to-warn claims along with negligence and concealment allegations.

The plaintiff, identified in court as Kaley G.M., is now 20 but alleges that social media addiction during her youth triggered serious mental health issues. Though TikTok and Snap were initially defendants in her case, she has reached settlements with them. Those agreements do not resolve the broader coordinated proceedings still pending before Judge Kuhl.

Opening statements began Feb. 9. Jurors have heard testimony from Anna Lembke, a professor of psychiatry and addiction medicine at Stanford University’s Addiction Medicine Dual Diagnosis Clinic, as well as Instagram CEO Adam Mosseri.

The plaintiff’s legal team includes attorneys from Kiesel Law LLP, The Lanier Law Firm, Panish Shea Ravipudi LLP, Wagstaff & Cartmell LLP and Beasley Allen Law Firm. Meta is represented by attorneys from Covington & Burling LLP, while YouTube’s defense is led by counsel from Wilson Sonsini Goodrich & Rosati PC.

As the courtroom waits for Wednesday — and for Zuckerberg’s testimony — the trial hangs in a fragile balance. One juror’s illness has slowed the machinery of justice, but the broader questions remain: When design meets dopamine, who bears responsibility?