Jurors resumed deliberations Tuesday in a closely watched US trial against Meta and YouTube after signaling difficulty in reaching a consensus on one of the defendants.

In a note to Judge Carolyn Kuhl, the jury said it was having trouble agreeing on liability for one of the companies and asked for guidance on how to proceed.

Kuhl instructed jurors to continue deliberating, warning that failure to reach a verdict could result in a retrial before a new jury, increasing costs for all parties.

No verdict was reached by the end of the day, extending deliberations in a case expected to influence hundreds of similar lawsuits across the United States.

Last week, jurors also sought clarification on how to calculate potential damages, suggesting that at least some members of the panel believe one or both companies may bear responsibility.

The lawsuit is among a growing number of cases accusing social media platforms of designing addictive products that harm young users’ mental health.

Plaintiffs argue that companies such as Meta and YouTube knowingly built systems that maximize user engagement while exposing minors to harmful content, including material linked to depression, eating disorders and self-harm.

The defense has leaned on Section 230 of the US Communications Decency Act, which generally shields platforms from liability for user-generated content.

However, the case centers on whether the platforms themselves — not their users — created defective and harmful products.

At the heart of the case is testimony from a 20-year-old California woman who said prolonged exposure to YouTube and Instagram contributed to her depression and suicidal thoughts starting in childhood.

Under cross-examination, she also cited personal and family issues, raising questions about whether social media was a primary cause of her mental health struggles.

Jurors are tasked with deciding whether the platforms should have known their services posed risks to minors, whether their design was negligent, and whether they were a substantial factor in causing harm.

The case is being treated as a “bellwether” trial, meaning its outcome could shape how courts handle a wave of similar claims against social media companies.

A split verdict — or failure to reach one — could delay that process.

“We’re reading tea leaves and we don’t know what they mean,” plaintiff’s attorney Mark Lanier said.