Ann Marie Mortimer

Ann Marie advises clients in high stakes litigation, acting as lead counsel in cases involving exceptional complexity and multiple jurisdictions. As a strategic problem solver, focusing on achieving business results in complex cases, Ann Marie has successfully resolved the most difficult cases facing her clients. She has an established track record in class action consumer claims litigation, focusing on data security, false advertising and unfair competition class actions. Her cross-disciplinary practice encompasses complex commercial transactions, litigation of distribution agreements, and toxic tort/environmental claims. In connection with counseling clients to manage downstream litigation risk, Ann Marie has conducted internal investigations and provided related counseling to the law departments of technology companies, financial institutions and consumer product manufacturers focused on compliance, best practices and enhanced integration with the stakeholder business units.

Ann Marie is head of the firm’s commercial litigation practice and founder and the managing partner of the Los Angeles office. Ann Marie’s practice is cross-disciplinary and includes significant business and class action consumer claims litigation experience in relation to data breach, consumer related labeling claims, as well as environmental, CERCLA and toxic tort multi-party litigation. In a highly-publicized and currently ongoing matter, Ann Marie served as the lead attorney defending an internet service provider in more than 40 related consumer class action lawsuits across several districts in state and federal court regarding a significant data breach. The breach has been deemed the largest data breach in history.

In connection with her litigation practice, Ann Marie routinely counsels clients on matters involving internal investigations and monitoring compliance of corporate legal departments, limiting litigation risk by auditing compliance to ensure a robust and transparent program. As part of her aggregate claims practice, Ann Marie has successfully decertified a nationwide products class action, and defeated class certification in multiple products, toxic tort, unfair competition and unfair trade practice cases. Ann Marie has tried toxic tort, commercial and products cases in state and federal courts throughout California. Ann Marie is admitted to practice before the Ninth Circuit Court of Appeals and the Northern, Eastern, Central and Southern Districts of California.

• Served as the lead lawyer defending an internet service provider in multiple consumer class action lawsuits across several districts in state and federal courts regarding a significant data breach. The data breach has been deemed the largest data breach in history. The lawsuit included more than 40 class actions.
• Serves as lead trial lawyer for a petroleum company, developing strategy on federal removal, particularly with respect to Clean Air issues, which are central to the case. This lawsuit represents a new frontier in environmental law – whether the actions of oil companies marketing their product to consumers constitutes public nuisance.
• Represents a major big box retailer in a class action lawsuit where plaintiff claimed hackers accessed Personally Identifiable Information associated with more than two million online shoppers as part of an alleged breach of the retailer’s computer network, and won dismissal of all causes of action including violation of the nascent California Consumer Privacy Act of 2018 and other California state laws. This is one of the first decisions dismissing a CCPA claim on the merits, earning recognition by the Daily Journal as a Top Defense Verdict of 2021.
• Serves as lead counsel representing a global hospitality and entertainment company in nine data security litigation class action lawsuits. The suit alleges the company failed to implement industry-standard data security measures that could have prevented a data breach that compromised guests' personal information, according to a putative class action.
• Represents a major retailer in a highly publicized California privacy case involving more than a dozen prominent retailers in a class action alleging retailers shared non-anonymized, individual consumer commercial activity and ID data with co-Defendant, a third-party service monitoring customers' shopping behavior to limit the amount of merchandise they can return. The suit alleges retailers collected and shared consumer data with the monitoring service without knowledge or consent of its customers, generating a "risk score" for each customer to mitigate fraudulent returns.
• Represents the largest social networking site in the world in at least a dozen statutory actions in a string of litigation filed against various worldwide app developers, web developers, online advertising companies, deceptive cloaking services and a data analytics firm – that are multi-jurisdictional in scope, and in several cases unprecedented—for deceptive practices that target the company and its users.
• Represented a luxury hospitality company in a class action lawsuit for an alleged security breach compromising hotel customers’ private identifiable information while booking hotel reservations.
• Represents a collective of multiple sanitation districts in a dispute with the cities of San Jose and Santa Clara over implementation of contracts that govern the Regional Wastewater Facility, which treats wastewater prior to release into the San Francisco Bay.
• Represented a major sports and casual apparel company in a putative class action in California federal court by a user of its fitness app claiming the company is liable for the theft of personal information from plaintiff and millions of others in a data breach.
• Represented pharmaceutical and life science companies, energy drink manufacturer, spirits manufacturer, cosmetics manufacturer, financial institutions, apparel manufacturer, sawmill and nationwide retail outlets in contract disputes, consumer claims and class actions.
• Represented internet service provider in Stored Communications Act, 17200 and related claims.
• Defended internet service provider in class action, 17200 and related data privacy claims.
• Represented consumer goods manufacturer in multiple nationwide putative class actions in unfair competition, false advertising and related statutory claims.
• Represented pharmaceutical companies, consumer product manufacturers, nationwide retailer, sawmill operator, and financial institutions in civil suits and regulatory enforcement actions involving coordinated internal investigations, litigation and defense counseling.
• Represented aerospace manufacturer in successful defense of thousands of claims in three separate trials related to allegedly harmful health exposures, property damage (including negligence, nuisance and trespass claims) and fear of cancer based on alleged exposures to chemicals including PCE, TCE and CR-6.
• Defended negligence, nuisance, trespass and personal injury claims related to alleged environmental contamination caused by historic manufacturing activities.
• Represented former saw mill operator in CERCLA allocation action, including defense of related negligence and nuisance claims.
• Served as nationwide counsel for medical device manufacturer in decertifying nationwide class and obtaining dismissal of product liability, unfair competition and CLRA claims.
• Represented pharmaceutical and medical device companies in negligence and strict liability claims related to heart valves, diet drugs, ED medication, antidepressants, diabetes medication, blood products and dialysis equipment.

• Named a Litigation Star, California, Benchmark Litigation, 2024-2025
• Recognized as a Women Leaders in Tech Law winner at the California Legal Awards, The Recorder, 2023-2024

• Recognized as a Leader in Privacy & Data Security: Litigation, USA-Nationwide, Chambers USA, 2024

• Named to Women of Influence: Attorneys, Los Angeles Business Journal, 2018-2020, 2022, 2024
• Named an Inspirational Women nominee, L.A. Times B2B Publishing, 2023
• Nominee for Executive of the Year at the Los Angeles Business Journal’s 2023 Women’s Leadership Symposium & Awards
• Named among “Top 100 Lawyers,” Los Angeles Business Journal, 2022-2024
• Lead trial counsel in one of the Top Defense Verdicts in California in 2021, Daily Journal, 2022
• Named an MVP in Cybersecurity & Privacy, Law360, 2020–2021
• Named to the inaugural list of Trailblazers West, The American Lawyer, 2021
• Named among the Top Women Lawyers in California, Daily Journal, 2017, 2019, 2021-2024
• Named a Top Cyber Lawyer in California, Daily Journal, 2020, 2022
• Recognized in The Los Angeles Times’ inaugural Business of Law Magazine as a Visionary, 2021-2023
• Named among the Top 100 Lawyers in California, Daily Journal, 2019, 2022-2023
• Named among California Trailblazers, The Recorder, 2019
• Named among Technology Trailblazers, National Law Journal, 2019
• Named among the Top Women Attorneys, Los Angeles Business Journal, 2018–2020, 2022
• Named among Leaders of Influence: Top Litigators in Los Angeles, Los Angeles Business Journal, 2018–2023
• Firm Attorney Nominee, Leaders in Law, Los Angeles Business Journal, 2018, 2020, 2021
• Recognized as a Litigation Trailblazer, National Law Journal, 2017
• Named among the Women Leaders in Tech Law, The Recorder, 2017
• Named among the Women Worth Watching, Profiles in Diversity Journal, 2017
• Finalist, Leaders in Law, Environmental Attorney, Los Angeles Business Journal, 2017

• Member, Women Lawyers Association of Los Angeles
• Member, DRI (Defense Research Institute)