In a high-stakes courtroom appearance that could reshape the future of online safety regulation, Mark Zuckerberg, CEO of Meta Platforms, testified before a Los Angeles jury in a landmark social media addiction trial examining Instagram’s impact on children’s mental health.

The lawsuit, brought by a now-20-year-old woman identified as “Kaley,” alleges that Instagram and YouTube were deliberately designed with addictive features that harmed her mental health when she began using the platforms as a child. Legal experts say the case could serve as a bellwether for hundreds of similar social media harm lawsuits nationwide.

At the core of the trial are allegations that Meta engineered Instagram’s features to maximize time spent on the app, particularly among minors. Plaintiff attorney Mark Lanier presented internal company documents referencing growth goals that included increasing user time on Instagram by 10 percent.

Zuckerberg acknowledged that earlier in Meta’s history, engagement metrics were emphasized. However, he told jurors that the company later shifted toward prioritizing “utility and value,” arguing that long-term platform success depends on positive user experiences rather than compulsive usage.

The legal question before the jury is whether Instagram was a “substantial factor” in the plaintiff’s reported mental health struggles, which include anxiety, body dysmorphia, online bullying, sextortion, and suicidal thoughts.

Meta has denied the allegations, stating that it has long invested in teen safety features and mental health research.

A significant portion of testimony focused on Instagram’s historical age verification practices. Although the platform has long required users to be at least 13 years old, internal documents from 2015 estimated that more than 4 million users under 13 were active on Instagram at the time.

Until late 2019, Instagram did not require new users to enter a birthdate; instead, users only had to confirm they were over 13. Critics argue that this system made it easy for underage children to bypass safeguards.

Zuckerberg testified that concerns about privacy influenced earlier design decisions but maintained that Meta eventually implemented stronger age verification measures. In 2021, the company expanded teen safety settings, including default private accounts and parental supervision tools.

The case has intensified public debate around social media age verification laws, platform accountability, and whether federal regulation is needed to protect minors online.

Another focal point of the trial involved Instagram’s use of appearance-altering “beauty filters.” Evidence presented suggested that Meta consulted experts who warned such filters could negatively affect teen self-image.

Instagram ultimately allowed user-generated filters but chose not to promote certain types within the app. Zuckerberg defended the decision as an attempt to balance free expression with user safety.

Mental health advocates argue that algorithm-driven exposure to curated and filtered images can exacerbate body image issues among adolescents, particularly teenage girls. The broader concern centers on whether social media algorithms amplify unrealistic beauty standards for profit.

Outside the courthouse, families who claim their children were harmed by social media gathered in solidarity. Some parents allege their children developed severe mental health challenges after prolonged exposure to Instagram and other platforms.

The emotional weight of the trial underscores a growing national conversation about whether social media companies prioritized growth and advertising revenue over youth safety protections.

Zuckerberg, who retains majority voting control of Meta, reiterated during testimony that his goal is to build products with long-term value and that the company has invested heavily in safety initiatives.

If Meta and YouTube are found liable, the consequences could extend far beyond financial damages. Legal analysts suggest potential outcomes may include:

The trial also tests a broader legal theory: whether tech companies can be held responsible for mental health harm allegedly linked to algorithmic design.

This case arrives amid increasing scrutiny from lawmakers and regulators examining the connection between social media use and rising rates of teen anxiety and depression.

The Zuckerberg testimony marks a pivotal moment in the debate over social media addiction, algorithm transparency, and child digital protection. As jurors weigh evidence, the verdict could redefine the responsibilities of technology companies in safeguarding young users.

For parents, policymakers, educators, and tech leaders, the outcome may influence how platforms approach engagement metrics, youth safety features, and mental health risk mitigation moving forward.

Whether this trial results in sweeping reform or reinforces existing legal protections for tech companies, it has already intensified public scrutiny over Instagram’s effects on children and the broader accountability of Big Tech in the digital age.