Instagram chief testifies in multi-state trial over alleged social media harms to youth

Adam Mosseri, who runs Instagram, took the stand in a federal courtroom in Oakland to defend the platform's record on safety and well-being for young users. The testimony is part of a trial in which four states (California, Colorado, Kentucky and New Jersey) accuse Meta of contributing to a youth mental health crisis by intentionally designing features that promote addictive use.

Mosseri pushed back on prosecutors who emphasized single metrics tied to one safety feature. He said Instagram launches many features aimed at safety and well-being and that the company works to improve those over time. He expressed frustration when questioning focused narrowly on low adoption of the "Take a Break" prompt.

The prosecution highlighted that few teens used the "Take a Break" tool when it was first introduced. The reporting summarized at trial notes that after Meta launched separate teen accounts in 2024, the company made the feature the default for teenage users. Mosseri disputed an implication that the company had concealed data, noting that Meta does not publish every internal statistic.

This Oakland federal trial is expected to last about six weeks and involves only four of the 29 states that filed suit in 2023. The other 25 states are slated to go to trial later. Meta also faces separate lawsuits in state courts, including an active case in Tennessee.

Earlier testimony in the Oakland trial included contentious exchanges over internal chats and documents. Francesco Fogu, Instagram's director of product design, had disputed testimony with plaintiffs' lawyers when internal materials were shown to the jury.

Mosseri previously testified in a California state-court trial involving a plaintiff identified as "KGM," who argued she became addicted to social media as a child. In that case, jurors found Meta and Google liable and awarded KGM a total of $6 million.

The states allege Meta knowingly designed features to increase compulsive use by children and that the company downplayed or hid evidence of risks. Prosecutors have focused on the company's product choices and internal communications to make that case.

The testimony reinforced a central dispute in the case: whether isolated product statistics reflect broader safety commitments and whether internal choices around teen features amount to deliberate design that increased harm. The trial will continue to probe internal documents, feature rollouts and how Meta communicated about teens' experience on Instagram.