California Deputy Attorney General Megan O’Neill characterised what she said was Meta’s strategy as: “Hook the users, hold them for as long as they can, harvest their data, and then hide the truth from the public.”

She told the eight-person jury that the strategy had been particularly effective with younger users. “It worked especially well for kids,” O’Neill said, adding that Meta “needed kids” while also needing to reassure parents and others responsible for their wellbeing that those children were safe.

According to the states, the alleged problem goes beyond individual posts or harmful content. Their case targets the architecture of the platforms themselves, including features such as infinite scrolling, algorithmic recommendations, push notifications, likes and filters that can keep users returning to their screens. The states argue that Meta developed these features with an understanding of how younger users respond to rewards and social feedback.

O’Neill told the court that Meta had studied aspects of adolescent brain development, including young people’s sensitivity to social feedback and their still-developing ability to control impulses.

Internal documents and the question of what Meta knew

A major part of the states’ case rests on internal Meta documents, research and employee communications that prosecutors say demonstrate the company knew about the risks faced by younger users.

O’Neill cited an internal Meta study titled “The young ones are the best ones” and argued that it showed the commercial importance of younger users to the company.

The Guardian reported that O’Neill pointed to an internal document stating: “Teens are hooked despite how it makes them feel. Instagram is addictive.” She also told the court that, in the states’ view, Meta repeatedly chose profits over the concerns raised by its own research.

Meta disputes that interpretation and argues that prosecutors are taking internal documents and informal employee comments out of context.

Paul Schmidt, Meta’s lawyer, told the court that there was “no dispute” that some social media users experience difficulties, but said research had not established a clear link between adolescent social media use and a lack of wellbeing.

Rejecting the argument that Meta deliberately built dangerous products, Schmidt said of the company: “They don’t believe they’re going to do well if people don’t like their service.”

Meta has also argued that its employees sometimes used loose language in internal conversations and that such remarks should not be treated as proof that the company formally regarded Instagram as addictive or intentionally sought to harm young users.

Arturo Béjar’s testimony puts Meta’s safety record under scrutiny

Former Meta safety engineer Arturo Béjar, the states’ first witness, told the jury that the company had taken a “don’t ask, don’t tell” approach to determining whether children under 13 were using its platforms, Reuters reported.

He also criticised the way safety considerations were handled when new products were launched.

“Many products were shipped into the world,” Béjar said, adding that safety “was not a consideration in how it was initially deployed.”

Béjar’s testimony has also focused on whether Meta’s existing safety mechanisms were effective.

According to AP, he criticised the company’s “Take a Break” feature as one that was effectively “designed to fail” because users must activate it themselves. Critics of Meta have similarly argued that voluntary time-management tools do little to address features that are designed to keep users scrolling.

In his second day of testimony, Béjar further alleged that Meta’s culture placed growth and engagement ahead of child safety, arguing that CEO Mark Zuckerberg’s priorities had an outsized influence on the company’s decision-making. Meta has denied the allegations against it.

Meta points to Teen Accounts and other safety measures

Meta, however, insists that it has introduced a wide range of protections for younger users and that its approach has evolved in response to concerns about child safety.

The company says its safeguards include restrictions on private messaging between adults and teenagers who are not connected, stronger enforcement against users under 13, reporting and blocking tools, and warnings and resources for searches related to suicide, self-harm and eating disorders. It has also highlighted its Teen Accounts, launched in 2024, which automatically place teenage users under stricter content and interaction settings.

Schmidt told the court that “there’s no question that some teens struggle to manage their time with social media,” pointing to Meta’s parental controls and other time-management tools as evidence that the company has attempted to address the issue.

Meta has said it has disabled more than one million accounts belonging to children under 13 and maintains that it takes enforcement of its minimum-age rules seriously, even though some children register with incorrect dates of birth.

But safety advocates argue that the measures do not go far enough. A 2025 report co-authored by Béjar and several online safety organisations found that many of the teen safety features they examined were either unavailable or did not function as advertised. Meta rejected the findings, describing the report as misleading and speculative.

What could Meta lose?

The immediate financial stakes are enormous, although the two sides differ sharply on the potential size of any penalty. According to Reuters, Meta has estimated that the damages it could face could theoretically reach $1.4 trillion, while the states have indicated a figure closer to $200 billion.

The lead states want the company to overhaul Facebook and Instagram, including possible changes to likes and infinite scrolling, time limits for younger users and stronger measures to keep children under 13 off the platforms. The jury is expected to issue an advisory verdict, while US District Judge Yvonne Gonzalez Rogers will determine Meta’s liability and any eventual penalties or remedies.

The case is part of a wider wave of litigation against Meta, TikTok, Snap and YouTube over allegations that their products harm young people.

The states are also drawing comparisons with litigation against tobacco companies, arguing that the case is about what Meta knew about potential harms and how it responded.

According to The Guardian’s report, Kentucky Attorney General Russell Coleman has explicitly invoked that history, saying the states intend to show that Meta concealed what it knew about harm to young users.

For Meta, the Oakland trial is therefore about more than one company’s safety record. As Béjar, Zuckerberg, Instagram chief Adam Mosseri and other witnesses take the stand in the coming weeks, the court will examine whether the design choices behind some of the world’s most widely used social media platforms can be separated from the alleged harms linked to them.

The outcome could determine how far regulators and courts can go in challenging the design of social media products because they encourage excessive use among young users.