In a rare digital privacy verdict, a federal jury held last month that Meta illegally eavesdropped on millions of women who entered menstrual and pregnancy health data into the Flo Period and Ovulation Tracker app (Flo app). Meta’s violation of the California Invasion of Privacy Act (CIPA) could trigger statutory damages running into the hundreds of millions of dollars. The verdict warns the multitudes of companies that receive data from a software development kit that they may have CIPA liability. This article, the first in a two-part series about CIPA lawsuits, examines the plaintiffs’ successful strategies to persuade the jury that Meta intentionally eavesdropped on them in Flo’s app without consent, and the dynamics of trying privacy cases before a jury, with commentary from privacy litigators at Farella, Braun & Martel, Holland & Knight, Troutman Amin and a plaintiffs’ attorney who reached a $725‑million settlement with Meta. Part two will discuss the implications of the verdict for other CIPA disputes and examine other important 2025 CIPA court decisions. See “Lessons From the Trenches: Winning Strategies for Defeating Pen Register Lawsuits” (Jun. 12, 2024).