2015 – Internal Meta documents estimate more than 4 million Instagram users are under 13, representing roughly 30 % of U.S. 10‑12‑year‑olds, and reveal early awareness that age‑verification tools are “not fit for purpose”[10].

2015‑2017 – Internal emails show Zuckerberg sets “stretch goals” to boost teen time on Instagram, labeling teenagers a top priority and discussing ways to increase daily usage[1].

Dec 2019 – Instagram begins requiring new users to enter a birthdate, a step toward enforcing its under‑13 ban[4].

Aug 2021 – Meta extends birth‑date verification to existing Instagram accounts, tightening age‑check enforcement[5].

2022 – Instagram leadership sets a “stretch goal” to raise average daily teen use from 40 minutes in 2023 to 46 minutes in 2026, reflecting a focus on time‑spend metrics[4].

2024 – Zuckerberg delivers a congressional apology for Instagram’s impact on youth mental health, a moment parents later cite while protesting the trial[4].

2024 – Surgeon General Vivek Murthy urges Congress to require tobacco‑style warnings on social‑media platforms, adding federal pressure to the litigation landscape[6].

Jan 21, 2026 – Snap settles a related social‑media‑addiction lawsuit days before jury selection, removing itself from the imminent Los Angeles trial[3].

Jan 26, 2026 – The landmark Los Angeles trial against Meta, TikTok and YouTube launches, with senior executives slated to testify over a projected six‑to‑eight‑week period[6].

Jan 27, 2026 – TikTok reaches a confidential settlement hours before jury selection, preventing it from being a defendant when the trial begins[2].

Jan 27, 2026 – Jury selection starts for the Instagram‑TikTok‑YouTube case, marking the first time the three firms face a jury and establishing the suit as a bellwether for roughly 1,500 similar actions[9].

Feb 18, 2026 – Zuckerberg testifies that he “wishes age‑verification improvements had arrived sooner,” acknowledges past under‑13 detection gaps, and says Meta now relies on content‑behavior signals to flag minors[10].

Feb 19, 2026 – Zuckerberg tells the jury that scientific research has not proven a causal link between social‑media use and mental‑health injury, admits former “time +10%” goals existed but claims the company has shifted to a “utility‑focused” approach, and rejects an internal memo urging a more authentic public persona as “simple feedback”[8].

Late Mar 2026 (expected) – The Los Angeles jury is scheduled to deliver a verdict, a decision that could set precedent for thousands of parallel lawsuits and force substantial platform changes[10].

Summer 2026 (planned) – Additional Los Angeles bellwether trials run later in the year, expanding the legal pressure on Meta, TikTok and YouTube[10].

June 2026 (planned) – A federal bellwether trial for school‑district plaintiffs begins in Oakland, California, potentially creating a nationwide benchmark for social‑media liability[9].

2026 (ongoing) – A separate New Mexico state case against Meta for alleged facilitation of sexual exploitation of minors proceeds in Santa Fe, with its outcome likely to influence other state‑level actions[7].