Jurors in Los Angeles began hearing competing narratives Tuesday in a landmark social media trial aimed at holding Meta and YouTube responsible for alleged harms to children linked to features plaintiffs characterize as addictive. The case centers on a plaintiff identified only by the initials “KGM,” whose matter is being used as a bellwether—meant to test how each side’s theories play with jurors before the litigation that follows. The dispute now pivots between the plaintiffs’ framing of the platforms as engineering addictive patterns and the remaining defendants’ argument that the evidence points to other causes and that the addiction claims do not fit KGM’s usage.
Plaintiff’s attorney Mark Lanier opened Monday in Los Angeles Superior Court by comparing the platforms to substances and warning jurors that the trial would be “easy as ABC,” which he said stands for “addicting the brains of children.” Lanier argued Meta and Google—describing them as “two of the richest corporations in history”—“engineered addiction in children’s brains,” and he laid out the plaintiffs’ case using internal emails, documents, and studies from Meta and YouTube, as well as YouTube’s parent company, Google.
Lanier pointed to a Meta study called “Project Myst,” which he said involved a survey of 1,000 teens and their parents about social media use. He told jurors the study’s results included findings that children who experienced “adverse events” such as trauma and stress were particularly vulnerable for addiction, and that parental supervision and controls made little impact. Lanier also highlighted internal Google documents that described some company products as resembling a casino and internal Meta communication in which one employee said Instagram was “like a drug” and that employees were “basically pushers.”
To rebut the specific claim that KGM was addicted to YouTube, Luis Li, the attorney for YouTube and Google, told jurors Tuesday that KGM’s own usage data did not align with the plaintiffs’ theory. Li said the five-year average of KGM’s watch time was 29 minutes per day and that her average daily time spent on YouTube Shorts was 1 minute and 14 seconds. Li also told jurors that features the plaintiffs challenged in their opening statement could be “disabled and modified” to match users’ preferences, and he argued that the concept of “infinite scroll” is limited rather than unlimited. “When you strip away all of the rhetoric … what you are left with is a simple truth. Infinite scroll is not infinite,” Li said. “In some cases, in this case, before this court, before you, the jury, it’s as little as a minute and 14 seconds. It’s not social media addiction when it’s not social media and it’s not an addiction.”
Li also emphasized KGM’s medical records, saying in sworn testimony KGM said she was not addicted to YouTube. He displayed three large boxes containing about 10,000 pages of medical records and told jurors that, within them, there would not be “a single example” of KGM being addicted to YouTube. Li said the sole reference to YouTube in those records involved KGM using a YouTube video to help with sleep at night when she felt anxious.
Meta attorney Paul Schmidt, who opened Tuesday’s defense segment for Meta, framed the trial around causation—whether the platforms were a substantial factor in KGM’s mental health struggles. Schmidt spent time reviewing KGM’s health records and highlighted that she had experienced difficult circumstances in childhood, including emotional abuse, body image issues, and bullying. He also played a clip from a video deposition from KGM’s mental health provider, Dr. Thomas Suberman, who said social media was “not the through-line of what I recall being her main issues,” adding that KGM’s struggles seemed largely tied to interpersonal conflicts and relationships.
Schmidt also acknowledged that many mental health professionals believe social media addiction can exist, but he said KGM’s providers—three of them—had never diagnosed her with it or treated her for it. He characterized KGM’s family environment as particularly unstable, pointing to KGM’s text messages and other testimony describing a volatile relationship with her mother. Earlier Monday, Schmidt’s colleague for Meta, Paul Schmidt, had also argued there is disagreement within the scientific community about social media addiction, including views that addiction does not exist or that it is not the right way to describe heavy social media use.
The bellwether format is designed to give both sides a yardstick for how their arguments might be received in a larger wave of lawsuits. In this case, TikTok and Snap are among the defendants that have settled, leaving Meta and YouTube as the two remaining defendants as the trial proceeds for about six to eight weeks. Jurors also are set to hear additional testimony later, including from KGM, who made a brief appearance Monday during Lanier’s statement and is expected to return to testify. Lanier said KGM started using YouTube at age 6 and Instagram at age 9, and that before she graduated from elementary school she had posted 284 videos on YouTube.
The trial also arrives amid broader legal pressure on social media companies over youth safety and mental health, with other cases set to unfold. Executives including Meta CEO Mark Zuckerberg are expected to testify in the Los Angeles matter, and a separate trial in New Mexico began with opening statements Monday involving allegations that Meta failed to protect young users from sexual exploitation tied to an undercover investigation. A federal bellwether trial set to begin in June in Oakland will also focus on school districts that sued social media platforms over harms to children, while more than 40 state attorneys general have filed lawsuits accusing Meta of deliberately designing features on Instagram and Facebook that, they argue, addict children.