Ann Rossum's practice focuses on commercial litigation, with an emphasis in class action defense. Her practice has included prosecuting and defending claims involving cybersecurity and data protection, consumer fraud and false advertising, trade secrets misappropriation, health care, antitrust, contract disputes, and the Fair Credit Reporting Act. Ann is experienced in all aspects of litigation, including trial.
Ann's recent matters include obtaining a multimillion dollar jury verdict, including punitive damages, on behalf of two large commercial insulation companies asserting misappropriation of trade secrets claims. She also represented a health care provider in parallel federal and state class actions that alleged tying and market leveraging. Ann's work in these matters focused on motion practice and pretrial preparation. Additionally she represented Applied Medical in an action in which it obtained a $33 million U.S. judgment and an anti-suit injunction precluding litigation in South Korea. Ann also has represented Experian Information Solutions in a wide range of matters at the trial and appellate court levels, including in multiple actions in which Experian obtained complete victories on summary judgment that were affirmed on appeal.
Ann also devotes significant time to pro bono work through Jones Day's Laredo Project, which provides assistance to detained refugees.
Before joining Jones Day, Ann clerked for the Honorable Marilyn L. Huff in the United States District Court for the Southern District of California. She is a member of the State Bar of California, the Association of Business Trial Lawyers, and the Orange County Bar Association.
- January 23, 2014
9th Circuit Mass Action View Remains Intact, Daily Journal
- January 22, 2020
Recent Trends in Class Action Settlements, Jones Day MCLE University
- July 17, 2018
Data Privacy: Customer Privacy v. Customer Profiling for Marketing Purposes, Jones Day Seminar
- University of San Diego (J.D. magna cum laude 2011; Order of the Coif; Editor-in-Chief, San Diego Law Review); Scripps College (B.A. in Economics and Politics cum laude 2008)
- California, all U.S. District Courts in California, U.S. District Court for District of Colorado, and U.S. Courts of Appeals for the Ninth and Tenth Circuits
- Law Clerk at the United States Attorney's Office, Southern District of California (2009); Field Representative for California Assemblywoman Lynn Daucher (2005-2006)
- Recognized by Super Lawyers in 2019 and 2020 as a class action/mass torts "Rising Star" for Southern California
- Law Clerk (2012) and Judicial Extern (2010) to Judge Marilyn L. Huff, U.S. District Court, Southern District of California