Ninth Circuit

Are AI prompts, and their generative outputs, discoverable in litigation? A handful of recent district court cases suggest the answer depends on whether the AI prompts and outputs constitute attorney work product.

In Tremblay v. OpenAI, Inc., 2024 WL 3748003 (N.D. Cal. Aug. 8, 2024), the court held that AI prompts written by lawyers can constitute opinion work product when used for litigation-related purposes. The court explained that AI “prompts were queries crafted by counsel and contain counsel’s mental impressions and opinions about how to interrogate [an AI tool], in an effort to vindicate Plaintiffs’ copyrights against the alleged infringements.” In so doing, the court squarely rejected defendant’s argument that AI prompts and outputs only rise to the level of fact work product as opposed to opinion work product. That distinction is important, as opinion work product is offered near-absolute protection from disclosure whereas fact work product is discoverable upon a showing of substantial need for the materials and an inability to secure a substantial equivalent without undue hardship.Continue Reading A Closer Look: The Discoverability of Artificial Intelligence Prompts

The Ninth Circuit partially reversed an order certifying multiple state‑law classes in litigation alleging that certain Ford Super Duty trucks suffer from a steering defect. See Lessin et al. v. Ford Motor Co., No. 25‑2211 (9th Cir. Feb. 11, 2026). While the Ninth Circuit affirmed parts of the class certification order, it held that the district court abused its discretion by certifying several classes without adequately evaluating whether plaintiffs could demonstrate the alleged defect with common evidence.Continue Reading Ninth Circuit Partially Reverses Certification of Classes Challenging Ford Trucks’ Alleged Steering “Shimmy”

The Ninth Circuit sent a strong message to companies considering relying on arbitration agreements introduced mid-litigation to defeat class-action litigation.  Avery v. TEKsystems, Inc., __ F.4th __, 2026 WL 218992 (9th Cir. Jan. 28, 2026)—in which the court described the defendant’s communications as “misleading,” “harmful,” “contradictory,” “disparaging,” and “inaccurate”—confirms the authority of district courts to refuse to enforce arbitration agreements that undermine Rule 23 procedures.Continue Reading Ninth Circuit Declines to Enforce “Misleading,” “Disparaging,” and “Confusing” Arbitration Agreement Mid‑Litigation

In 2025, courts continued to issue significant decisions concerning the application of wiretap and privacy laws to pixels, session replay, and other website technologies. Over the past year, we have featured posts discussing claims regarding website analytics and advertising tools brought under the federal Wiretap Act, the California Invasion of Privacy Act (“CIPA”), the Video Privacy Protection Act (“VPPA”), and other laws.  A selection of posts highlighting important developments in this area is below. Continue Reading Website Wiretapping Roundup: 2025 Decisions and Developments 

On October 27, 2025, the Ninth Circuit affirmed in a memorandum opinion the dismissal of a proposed class action asserting that the owner of a cybersecurity browser extension violated the California Invasion of Privacy Act (“CIPA”) and the Electronic Communications Privacy Act (“ECPA”) by intercepting communications between extension-users and search engines. Karwowski v. Gen Digital, Inc., No. 24-7213, 2025 WL 3002610 (9th Cir. Oct. 27, 2025) (mem.).  The Court held that the Plaintiffs failed to allege that the Defendant was not a party to the communications.Continue Reading Ninth Circuit Affirms Dismissal of Wiretap Claims Based on Party Exception

In a win for businesses using third-party technologies to power their websites, a California federal court applied the Ninth Circuit’s recent decision in Popa v. Microsoft Corporation to dismiss a “pen register” claim brought under the California Invasion of Privacy Act (“CIPA”) for lack of Article III standing.  Khamooshi v. Politico LLC, No. 24-cv-07836-SK, 2025 WL 2822879 (N.D. Cal. Oct. 2, 2025).  “As in Popa,” the Khamooshi court held that the plaintiffs—who alleged the collection of their device type, browser type, and “device fingerprints”—“identifie[d] no embarrassing, invasive, or otherwise private information collected,” as required to establish an Article III injury. Continue Reading Court Applies Popa to Dismiss CIPA Pen Register Claim for Lack of Article III Standing

In a win for implied preemption, the Ninth Circuit recently affirmed dismissal of supplement marketing claims under California’s Unfair Competition Law (UCL).  The case, Bubak v. Golo, LLC, No. 24-492 (9th Cir. Oct. 9, 2025), held that the plaintiff’s UCL claim was impliedly preempted because it depended entirely on alleged violations of the federal Food, Drug, and Cosmetic Act (FDCA), which may be enforced only by the federal government.Continue Reading Ninth Circuit Affirms Dismissal of Supplement Marketing Claims as Impliedly Preempted

In 2018, the Ninth Circuit held in Lusnak v. Bank of America, N.A. that California’s interest-on-escrow law was not preempted by the National Bank Act because the California law did not prevent or significantly interfere with the bank’s exercise of its powers.  883 F.3d 1185 (9th Cir. 2018).  Six years after Lusnak, the Supreme Court held in Cantero v. Bank of America that test for preemption under the National Bank Act requires courts to “make a practical assessment of the nature and degree of the interference caused by a state law,” and courts should do so by engaging in a “nuanced comparative analysis” that compares the interference caused by previous state laws that were challenged as preempted before the Supreme Court to the law at issue.  602 U.S. 205, 219–21 (2024). Continue Reading Post-Cantero, Ninth Circuit Allows Prior National Bank Act Preemption Decision To Remain Standing

A divided Ninth Circuit panel recently affirmed a district court’s denial of class certification based on a lack of predominance.  See Ambrosio v. Progressive Preferred Ins. Co., 2025 WL 2628179 (9th Cir. Sept. 12, 2025).  The plaintiffs sought to represent a class of drivers asserting breach-of-contract and other related claims against an auto insurer.  The drivers alleged the insurer’s use of a “projected sold adjustment” (“PSA”) to calculate the market value of insured drivers’ vehicles after a total loss led the insurer to uniformly underestimate vehicle value, which they contended violated the terms of their insurance policies.  Agreeing with the district court’s reasoning, the Ninth Circuit held that, because the insurer’s use of the PSA did not by itself violate the terms of the policies, each plaintiff would need to adduce individual evidence to prove that the PSA had caused them measurable damages—an essential element of a claim for breach of contract under Arizona law. Continue Reading Ninth Circuit Affirms Denial of Class Certification Finding Lack of Predominance

On August 15, the Ninth Circuit Court of Appeals affirmed the dismissal of a class action complaint in Gibson v. Cendyn Group, No. 24-3576, rejecting plaintiffs’ arguments that Las Vegas hotels violated Section 1 of the Sherman Act through their common use of revenue management software.  The decision follows…

Continue Reading Ninth Circuit Rejects Vegas Hotel Algorithmic Price Fixing Claims