LOS ANGELES (AP) — Adam Mosseri, the head of Meta’s Instagram, testified Wednesday during a landmark social media trial in Los Angeles that he disagrees with the idea that people can be clinically addicted to social media platforms.

The question of addiction is a key pillar of the case, where plaintiffs seek to hold social media companies responsible for harms to children who use their platforms. Meta Platforms and Google’s YouTube are the two remaining defendants in the case, which TikTok and Snap have settled.

At the core of the Los Angeles case is a 20-year-old identified only by the initials “KGM,” whose lawsuit could determine how thousands of similar lawsuits against social media companies would play out. She and two other plaintiffs have been selected for bellwether trials — essentially test cases for both sides to see how their arguments play out before a jury.

Mosseri, who’s headed Instagram since 2018 said it’s important to differentiate between clinical addiction and what he called problematic use. The plaintiff’s lawyer, however, presented quotes directly from Mosseri in a podcast interview a few years ago where he used the term addiction in relation to social media use, but he clarified that he was probably using the term “too casually,” as people tend to do.

Mosseri said he was not claiming to be a medical expert when questioned about his qualifications to comment on the legitimacy of social media addiction, but said someone “very close” to him has experienced serious clinical addiction, which is why he said he was “being careful with my words.”

He said he and his colleagues use the term “problematic use” to refer to “someone spending more time on Instagram than they feel good about, and that definitely happens.”

It’s “not good for the company, over the long run, to make decisions that profit for us but are poor for people’s well-being,” Mosseri said.

Mosseri and the plaintiff’s lawyer, Mark Lanier, engaged in a lengthy back-and-forth about cosmetic filters on Instagram that changed people’s appearance in a way that seemed to promote plastic surgery.

“We are trying to be as safe as possible but also censor as little as possible,” Mosseri said.

In the courtroom, bereaved parents of children who have had social media struggles seemed visibly upset during a discussion around body dysmorphia and cosmetic filters. Meta shut down all third-party augmented reality filters in January 2025. The judge made an announcement to members of the public on Wednesday after the displays of emotion, reminding them not to make any indication of agreement or disagreement with testimony, saying that it would be “improper to indicate some position.”

During cross examination, Mosseri and Meta lawyer Phyllis Jones tried to reframe the idea that Lanier was suggesting in his questioning that the company is looking to profit off of teens specifically.

Mosseri said Instagram makes “less money from teens than from any other demographic on the app,” noting that teens don’t tend to click on ads and many don’t have disposable income that they spend on products from ads they receive. During his opportunity to question Mosseri for a second time, Lanier was quick to point to research that shows people who join social media platforms at a young age are more likely to stay on the platforms longer, which he said makes teen users prime for meaningful long-term profit.

“Often people try to frame things as you either prioritize safety or you prioritize revenue,” Mosseri said. “It’s really hard to imagine any instance where prioritizing safety isn’t good for revenue.”

Meta CEO Mark Zuckerberg is expected to take the stand next week.

In recent years, Instagram has added a slew of features and tools it says have made the platform safer for young people. But this does not always work. A report last year, for instance, found that teen accounts researchers created were recommended age-inappropriate sexual content, including “graphic sexual descriptions, the use of cartoons to describe demeaning sexual acts, and brief displays of nudity.”

In addition, Instagram also recommended a “range of self-harm, self-injury, and body image content” on teen accounts that the report says “would be reasonably likely to result in adverse impacts for young people, including teenagers experiencing poor mental health, or self-harm and suicidal ideation and behaviors.” Meta called the report “misleading, dangerously speculative” and said it misrepresents its efforts on teen safety.

Meta is also facing a separate trial in New Mexico that began this week.

WASHINGTON (AP) — The U.S. Food and Drug Administration is refusing to consider Moderna’s application for a new flu vaccine made with Nobel Prize-winning mRNA technology, the company announced Tuesday.

The news is the latest sign of the FDA’s heightened scrutiny of vaccines under Health Secretary Robert F. Kennedy Jr., particularly those using mRNA technology, which he has criticized before and after becoming the nation’s top health official.

Moderna received what’s called a “refusal-to-file” letter from the FDA that objected to how it conducted a 40,000-person clinical trial comparing its new vaccine to one of the standard flu shots used today. That trial concluded the new vaccine was somewhat more effective in adults 50 and older than that standard shot.

The letter from FDA vaccine director Dr. Vinay Prasad said the agency doesn’t consider the application to contain an “adequate and well-controlled trial” because it didn’t compare the new shot to “the best-available standard of care in the United States at the time of the study.” Prasad’s letter pointed to some advice FDA officials gave Moderna in 2024, under the Biden administration, which Moderna didn’t follow.

According to Moderna, that feedback said it was acceptable to use the standard-dose flu shot the company had chosen — but that another brand specifically recommended for seniors would be preferred for anyone 65 and older in the study. Still, Moderna said, the FDA did agree to let the study proceed as originally planned.

The company said it also had shared with FDA additional data from a separate trial comparing the new vaccine against a licensed high-dose shot used for seniors.

The FDA “did not identify any safety or efficacy concerns with our product” and “does not further our shared goal of enhancing America’s leadership in developing innovative medicines,” Moderna CEO Stephane Bancel said in a statement.

It’s rare that FDA refuses to file an application, particularly for a new vaccine, which requires companies and FDA staff to engage in months or years of discussions.

Moderna has requested an urgent meeting with FDA, and noted that it has applied for the vaccine’s approval in Europe, Canada and Australia.

In the last year, FDA officials working under Kennedy have rolled back recommendations around COVID-19 shots, added extra warnings to the two leading COVID vaccines — which are made with mRNA technology — and removed critics of the administration’s approach from an FDA advisory panel.

Kennedy announced last year that his department would cancel more than $500 million in contracts and funding for the development of vaccines using mRNA.

FDA for decades has allowed vaccine makers to quickly update their annual flu shots to target the latest strains by showing that they trigger an immune response in patients. That’s a far more efficient approach than running long-term studies tracking whether patients get the flu and how they fare. In an internal memo last year, Prasad wrote that the streamlined method would no longer be permitted – leading more than a dozen former FDA commissioners to pen an editorial condemning the statements.

LOS ANGELES (AP) — Comparing social media platforms to casinos and addictive drugs, lawyer Mark Lanier delivered opening statements Monday in a landmark trial in Los Angeles that seeks to hold Instagram owner Meta and Google’s YouTube responsible for harms to children who use their products.

Instagram’s parent company Meta and Google’s YouTube face claims that their platforms addict children through deliberate design choices that keep kids glued to their screens. TikTok and Snap, which were originally named in the lawsuit, settled for undisclosed sums.

Jurors got their first glimpse into what will be a lengthy trial characterized by dueling narratives from the plaintiffs and the two remaining defendants.

Meta lawyer Paul Schmidt spoke of the disagreement within the scientific community over social media addiction, with some researchers believing it doesn’t exist, or that addiction is not the most appropriate way to describe heavy social media use.

Lawyers representing YouTube will begin their opening statement on Tuesday.

‘Addicting the brains of children’

Lanier, the plaintiff’s lawyer, delivered lively first remarks where he said the case will be as “easy as ABC” — which stands for “addicting the brains of children.” He said Meta and Google, “two of the richest corporations in history,” have “engineered addiction in children’s brains.”

He presented jurors with a slew of internal emails, documents and studies conducted by Meta and YouTube, as well as YouTube’s parent company, Google. He emphasized the findings of a study Meta conducted called “Project Myst” in which they surveyed 1,000 teens and their parents about their social media use. The two major findings, Lanier said, were that Meta knew children who experienced “adverse events” like trauma and stress were particularly vulnerable for addiction; and that parental supervision and controls made little impact.

He also highlighted internal Google documents that likened some company products to a casino, and internal communication between Meta employees in which one person said Instagram is “like a drug” and they are “basically pushers.”

At the core of the Los Angeles case is a 20-year-old identified only by the initials “KGM,” whose case could determine how thousands of other, similar lawsuits against social media companies will play out. She and two other plaintiffs have been selected for bellwether trials — essentially test cases for both sides to see how their arguments play out before a jury.

Plaintiff grew up using YouTube, Instagram

KGM made a brief appearance after a break during Lanier’s statement and she will return to testify later in the trial. Lanier spent time describing KGM’s childhood, focusing particularly on what her personality was like before she began using social media. She started using YouTube at age 6 and Instagram at age 9, Lanier said. Before she graduated elementary school, she had posted 284 videos on YouTube.

The outcome of the trial could have profound effects on the companies’ businesses and how they will handle children using their platforms.

Lanier said the companies’ lawyers will “try to blame the little girl and her parents for the trap they built,” referencing the plaintiff. She was a minor when she said she became addicted to social media, which she claims had a detrimental impact on her mental health.

Lanier said that despite the public position of Meta and YouTube being that they work to protect children, their internal documents show an entirely different position, with explicit references to young children being listed as their target audiences.

The attorney also drew comparisons between the social media companies and tobacco firms, citing internal communication between Meta employees who were concerned about the company’s lack of proactive action about the potential harm their platforms can have on children and teens.

“For a teenager, social validation is survival,” Lanier said. The defendants “engineered a feature that caters to a minor’s craving for social validation,” he added, speaking about “like” buttons and similar features.

Meta pushes back

In his opening statement representing Meta, Schmidt said the core question in the case is whether the platforms were a substantial factor in KGM’s mental health struggles. He spent much of his time going through the plaintiff’s health records, emphasizing that she had experienced many difficult circumstances in her childhood, including emotional abuse, body image issues and bullying.

Schmidt presented a clip from a video deposition from one of KGM‘s mental health providers, Dr. Thomas Suberman, who said social media was “not the through-line of what I recall being her main issues,” adding that her struggles seemed to largely stem from interpersonal conflicts and relationships. He painted a picture — with KGM’s own text messages and testimony pointing to a volatile home life — of a particularly troubled relationship with her mother.

Schmidt acknowledged that many mental health professionals do believe social media addiction can exist, but said three of KGM’s providers — all of whom believe in the form of addiction — have never diagnosed her with it, or treated her for it.

Schmidt emphasized to the jurors that the case is not about whether social media is a good thing or whether teens spend too much time on their phones or whether the jurors like or dislike Meta, but whether social media was a substantial factor in KGM’s mental health struggles.

A reckoning for social media and youth harms

A slew of trials beginning this year seek to hold social media companies responsible for harming children’s mental well-being. Executives, including Meta CEO Mark Zuckerberg, are expected to testify at the Los Angeles trial, which will last six to eight weeks. Experts have drawn similarities to the Big Tobacco trials that led to a 1998 settlement requiring cigarette companies to pay billions in health care costs and restrict marketing targeting minors.

A separate trial in New Mexico, meanwhile, also kicked off with opening statements on Monday. In that trial, Meta is accused of failing to protect young users from sexual exploitation, following an undercover online investigation. Attorney General Raúl Torrez in late 2023 sued Meta and Zuckerberg, who was later dropped from the suit.

A federal bellwether trial beginning in June in Oakland, California, will be the first to represent school districts that have sued social media platforms over harms to children.

In addition, more than 40 state attorneys general have filed lawsuits against Meta, claiming it is harming young people and contributing to the youth mental health crisis by deliberately designing features on Instagram and Facebook that addict children to its platforms. The majority of cases filed their lawsuits in federal court, but some sued in their respective states.

TikTok also faces similar lawsuits in more than a dozen states.