Freshly unsealed documents from a federal court in Northern California have intensified scrutiny of Meta after revealing that the company once conducted — and later shelved — internal research into Facebook’s psychological impact. The project, known as Project Mercury, began in 2020 as an effort to understand how using the platform affected users’ emotional wellbeing.
Meta partnered with research firm Nielsen to run the study, which involved asking a group of Facebook users to deactivate their accounts for one week. Participants who stepped away reported meaningful improvements in their mental health, including lower levels of anxiety, depression, loneliness and negative self-comparison. According to the filing, these findings were significant enough that researchers expected the project to continue or expand.
Instead, Project Mercury was halted. The results were neither published nor shared with lawmakers, even as Congress was actively examining the effects of social media on children and teens.
Internal Emails Show the Company Questioned the Results
The lawsuit — filed by school districts accusing Meta and other tech companies of contributing to a youth mental health crisis — includes internal correspondence describing how Meta executives addressed the study’s findings. According to these communications, the company’s leadership cast doubt on the validity of the results, arguing that participants’ improved wellbeing might be tied to the negative public discourse surrounding social media rather than the act of logging off.
The documents also recount debates among researchers inside Meta. At least one team member argued that the survey suggested a causal relationship between Facebook usage and stress from social comparison. One internal exchange went so far as to compare Meta’s handling of the data to the behaviors of industries that once downplayed health risks associated with their products.
The filings say Meta continued to tell lawmakers that it lacked definitive evidence of harm to teenage users, particularly girls — a position that the plaintiffs argue was inconsistent with the company’s internal research at the time.
Design Choices Allegedly Limited the Effectiveness of Youth Safety Tools
Beyond Project Mercury, the court filings describe a broader pattern regarding Meta’s approach to safety features for young users. Many tools meant to protect teens were built in ways that made them difficult to find or rarely used. Some stronger protections that had been tested internally were reportedly rejected because they posed a risk to engagement metrics, which influence user growth and advertising performance.
The lawsuit also claims that enforcement thresholds for serious violations were set so high that users had to commit repeated offenses — sometimes more than a dozen — before they were permanently removed. According to the plaintiffs, this system allowed harmful behavior, including sexual exploitation, to persist longer than it should have.
Algorithms Accused of Amplifying Harmful Content for Teens
Another major theme in the filing focuses on Meta’s algorithmic recommendations. The documents argue that engagement-driven systems sometimes pushed teens toward content linked to body image issues, extreme dieting, or other topics known to create psychological strain.
Internal safety teams, the documents claim, attempted to address these problems but were often deprioritized. In one example highlighted by the plaintiffs, executives explored ways to increase privacy around teen livestreams. While such a move could limit visibility for parents or educators, internal discussions suggested it might help retain younger users by giving them more autonomy — a trade-off critics say puts business interests ahead of safety.
Meta Responds, Denying Any Effort to Hide Negative Findings
Meta spokesperson Andy Stone has rejected claims that the company concealed research or ignored evidence of potential harm. He told Reuters that the deactivation study was discontinued due to methodological weaknesses, not to suppress its results. Stone also emphasized the company’s long-term investment in tools aimed at teen safety, parental supervision, and content reporting.
Meta has argued that the documents referenced in the lawsuit are being presented out of context, and that its efforts to strike certain materials from the filing relate to privacy concerns, not an attempt to block the release of damaging evidence.
Other Tech Giants Also Face Questions About Youth Safety
The multidistrict lawsuit extends beyond Meta, pulling Google, Snap, and TikTok into the broader conversation about how tech platforms affect young users. According to the filings, internal communications across these companies show varied levels of awareness about how platform features can shape teen behavior.
One internal TikTok presentation, cited in the lawsuit, contrasted the educational and highly moderated content offered to users of Douyin, the company’s Chinese platform, with the more attention-grabbing content often shown to American teens. TikTok disputes both the phrasing and the interpretation of these documents.
Snapchat’s internal emails reportedly acknowledged that features like “Snapstreaks” — which encourage daily messaging — helped cultivate compulsive use patterns among younger users.
