Allison Libeu

Lauded as one of the “brightest litigators across the U.S.” in Benchmark Litigation, and described by clients to Chambers as “fantastic” and “a powerful oral arguer,” Allison Libeu provides creative, practical, and strategic counsel to help her clients resolve complex commercial disputes and protect their business interests. Ms. Libeu litigates high-stakes business disputes across a variety of areas, including business torts, contracts, trademark infringement, and trade secrets.

Ms. Libeu has successfully prosecuted and defended disputes involving company founders; the termination of C-suite executives; and claims that frequently arise in such cases, including claims related to breach of fiduciary duty and unfair competition as well as violation of nondisclosure, noncompete, and nonsolicitation agreements. Her national practice includes litigation at the trial and appellate levels in both federal and state courts, in addition to U.S.-based and international arbitration.

Ms. Libeu has been named to the Daily Journal’s lists of “Top Women Lawyers” and “Top 40 Under 40,” included among the “Top 250 Women in Litigation,” “Litigation Stars,” “40 & Under” and “Future Stars” by Benchmark Litigation, and named among “Leaders of Influence: Litigators & Trial Attorneys” and “Women of Influence: Attorneys” by the Los Angeles Business Journal, among many other accolades.

• Ms. Libeu currently represents Joe Kiani, founder and CEO of Masimo Corp., a global technology company, in litigation playing out across the country surrounding Kiani’s departure from the company and its refusal to pay approximately $450 million due under his employment agreement. Among several recent victories, Ms. Libeu in March 2026 persuaded an Orange County Superior Court judge to disqualify Quinn Emanuel from representing several Masimo directors in a suit brought by Kiani. She secured another win in April, when the Delaware Chancery Court granted the firm’s motion to dismiss a suit Masimo filed alleging certain provisions of Kiani’s employment agreement are void or unenforceable.

• Ms. Libeu currently represents Epic Games in cases across multiple jurisdictions claiming that the company intentionally designed its “Fortnite” video game to addict players. The cases raise novel theories of liability and important First Amendment issues relating to digital media. In key victories for Epic, plaintiffs in more than two dozen of the suits dismissed their cases against Ms. Libeu’s client in 2024, 2025 and 2026. In another seven cases against Epic, Ms. Libeu recently successfully compelled the plaintiffs to arbitrate their claims.

• On behalf of Amazon and Twitch, Ms. Libeu secured a first-of-its-kind decision in New York state, with the New York Supreme Court, Appellate Division, dismissing lawsuits alleging her clients and other social media companies were liable for a fatal mass shooting in Buffalo, New York. The plaintiffs—victims of the shooting and their family members—claimed the shooter was radicalized by extremist and racist content on social media and that his ability to livestream on Twitch motivated him to commit the crimes. The Appellate Division dismissed Amazon and Twitch, agreeing with Ms. Libeu’s arguments that the First Amendment protects their conduct, that Section 230 affords them immunity, and that the shooter was not radicalized on Twitch. The case is currently on appeal to the New York Court of Appeals.

• Ms. Libeu obtained a $293 million verdict for Monster Energy Company in a high-profile lawsuit involving claims of false advertising, tortious interference and trade secrets theft against Vital Pharmaceuticals, Inc. (VPX)—the third-largest energy drink manufacturer in the U.S.—and its owner and CEO. The verdict is believed to be the largest false advertising award in history. The outcome was a complete victory for the client with findings in Monster’s favor on every claim. She also argued before and convinced the U.S. Court of Appeals for the Ninth Circuit to affirm the trial judgment and permanent injunction. The U.S. Supreme Court cemented the win in June 2026, when it denied the petition for certiorari.

• Ms. Libeu won among “the largest-ever U.S. trademark awards” (Reuters) for Monster Energy Company against rival beverage company Vital Pharmaceuticals, Inc. Following a two-week trial, the arbitrator held that VPX’s Bang Energy does not contain advertised muscle-building creatine and infringed on the “Bang” trademark. In the significant ruling, the arbitrator awarded Monster and Orange Bang $175 million in damages, nearly $10 million in attorney’s fees and costs, and a 5% royalty on all future sales of Bang Energy (with over $1.5 billion in annual sales). The award came after Ms. Libeu cross-examined Vital Pharmaceuticals’ damages expert and obtained critical admissions about his methodology that undercut his opinions, which resulted in the arbitrator rejecting his disgorgement and royalty theories as a “post-litigation contrivance.”

• J.D., Order of the Coif, UCLA School of Law, 2006
• B.A., Political Science, summa cum laude, Chapman University, 2003