LOS ANGELES, United States, Feb 3, 2026 (BSS/AFP) - The start of a landmark social media addiction trial was delayed on Monday, with prospective jurors told to return to the Los Angeles courthouse later in the week.

Opening remarks had been expected to begin Tuesday, once jury selection is complete. But the process was interrupted because an attorney fell ill, according to a person with knowledge of the situation.

An order posted by the court said the proceedings will resume on Thursday.

The trial is being keenly watched because of its potential to establish a legal precedent on whether social media companies deliberately designed their platforms to addict children.

The case in a California state court in Los Angeles is being called a bellwether proceeding because its outcome could set the tone for a tidal wave of similar litigation across the United States.

Defendants at the trial are Alphabet and Meta, the tech titans behind YouTube and Instagram.

Social media firms are accused in hundreds of lawsuits of addicting young users to content that has led to depression, eating disorders, psychiatric hospitalization and even suicide.

Lawyers for the plaintiffs are explicitly borrowing strategies used in the 1990s and 2000s against the tobacco industry, which faced a similar onslaught of lawsuits arguing that companies sold a harmful product.

The trial before Judge Carolyn Kuhl focuses on allegations that a young woman identified only by the initials K.G.M. suffered severe mental harm because she became addicted to social media as a child.

Internet titans have argued that they are shielded by Section 230 of the US Communications Decency Act, which frees them of responsibility for what social media users post.

However, this case argues that those firms are culpable for business models designed to hold people's attention and to promote content that winds up harming their mental health.

"The allegations in these complaints are simply not true," said Jose Castaneda, a YouTube spokesperson.

"Providing young people with a safer, healthier experience has always been core to our work," he added.

Meta has also rejected the allegations.

Snapchat and TikTok were named as defendants in the suit, but struck settlement deals as the trial was poised to start. The terms were not disclosed.