Margaux Poueymirou

Margaux represents plaintiffs and defendants in antitrust, intellectual property, and artificial intelligence disputes, using her experience on both sides of the “v” to craft tactical litigation strategies that resonate with judges, juries, and regulators alike. 

Margaux has litigated antitrust cases ranging from monopolization to price-fixing to competition issues involving emerging technologies on behalf of individuals, health insurers, and major corporations. Margaux also has in-depth experience litigating a variety of matters in the technology sector, including cases at the intersection of open-source licensing, intellectual property, and artificial intelligence. Presently, Margaux represents rights holders in pioneering litigations against major tech companies over the use of copyrighted works to train generative AI models.

An inaugural public interest fellow at the University of California, Irvine School of Law, Margaux regularly dedicates her time to social impact causes. She has drafted amicus briefs on gun regulation for organizations and successfully argued compassionate release motions for incarcerated individuals under the First Step Act.

Margaux's recent experience includes: 

• Representing a putative class of authors alleging copyright violations against Meta Platforms for pirating their registered works for use as AI training data for Meta’s Llama Large Language Models
• Representing a putative class of authors alleging copyright violations against OpenAI for pirating their registered works for use as AI training data for OpenAI’s Large Language Models
• Representing software programmers against GitHub, Microsoft, and OpenAI for using their open-source software code in violation of open-source licensing terms and the Digital Millennium Copyright Act
• Defended a major healthcare company in an antitrust dispute brought by state attorney general alleging collusion through a group purchasing organization
• Defended a major government contractor in an antitrust “no poach” claim
• Represented a major healthcare company in multidistrict litigation involving price-fixing and collusion in the generic pharmaceutical drug industry

Co-author, Why AI's Use of Shadow Libraries Should Alarm Us All, Daily Journal (June 2025)

Chapter 11: Indirect Purchasers, California Antitrust and Unfair Competition Law Revised Edition (2024)

Penn State Hershey, A Cautionary Tale for Antitrust Litigators, Competition Policy International Antitrust Chronicle (2019)

Schuette v. Coalition to Defend Affirmative Action & the Death of the Political Process Doctrine, UC Irvine Law Review (2017)

Co-author, Harris v. Quinn and the Contradictions of Compelled Speech, 48 Loy. L.A. L. Rev. 439 (2015)