About Sean
Sean A. Petterson: Leading Cybersecurity and Data Breach Litigation Attorney
Sean A. Petterson is a highly respected partner at Lieff Cabraser, specializing in complex litigation involving data breaches and cybersecurity incidents. With a focused dedication to protecting clients’ rights and securing substantial compensation, Mr. Petterson is a leading national expert in nationwide data breach class actions, consistently recognized for his strategic approach and success.
As a member of the firm’s cybersecurity/data privacy practice group, Mr. Petterson’s expertise centers around guiding clients through the intricate legal landscape of these cases, from initial investigation to settlement negotiations and trial. He possesses a deep understanding of the legal and technical complexities surrounding data breaches, including the Illinois Biometric Information Privacy Act (BIPA), Telephone Consumer Protection Act (TCPA), and securities litigation.
Mr. Petterson’s recent achievements reflect his profound understanding and strategic prowess. He was recently appointed to the Plaintiffs’ Steering Committee in the nationwide In re: Snowflake, Inc., Data Security Breach Litigation, demonstrating his crucial role in leading these significant cases. He also plays a key role in ongoing nationwide data breach litigation against Marriott and Quest Labs, utilizing his expertise to aggressively pursue claims and advocate for his clients’ interests, particularly through expert analysis.
Beyond his nationally recognized work, Mr. Petterson is a dedicated advocate for individuals and institutions harmed by data breaches. He represents truck drivers in two proposed class actions brought under the Illinois BIPA against technology providers, highlighting his commitment to protecting consumer privacy and holding companies accountable. Furthermore, he’s a champion for corporate clients, having successfully represented The Boeing Company’s officers and directors in a shareholder derivative action, resulting in a landmark $237.5 million settlement. His representation of the New York State Comptroller Thomas P. DiNapoli, as trustee of the New York State Common Retirement Fund, and the Fire and Police Pension Association of Colorado in connection with the 737 MAX litigation showcased his ability to tackle high-stakes, complex legal matters.
Mr. Petterson’s contributions extend beyond data breach litigation. He is also a member of the firm’s securities practice group, leveraging his extensive legal background to navigate and resolve complex securities disputes. Notably, he represented Co-Lead Plaintiffs in a derivative action against Wells Fargo’s current and former officers and directors stemming from the illicit sales practices scandal, ultimately securing a $240 million settlement – the largest insurer-funded derivative settlement in history.
Mr. Petterson’s work with the consumer practice group has also resulted in significant victories, specifically in cases brought under the TCPA, protecting clients from unlawful telephone marketing practices.
Currently, he is representing retired pastors in the In Re: AME Church Employee Retirement Fund Litigation, MDL No. 3035, demonstrating his commitment to diverse legal challenges.
Recognition of Mr. Petterson’s expertise and dedication is consistently acknowledged by leading legal organizations. He has been named “Ones to Watch” by Best Attorneys from 2021-2025 and a Rising Star for the New York Metro Area by Super Lawyers from 2021-2024. His thought leadership is further demonstrated through his presentations at conferences focusing on Article III standing and damages in data breach litigation.
Prior to joining Lieff Cabraser, Mr. Petterson honed his legal skills as an associate at Boies Schiller Flexner, LLP from 2015-2018, solidifying his foundation in litigation.
Education & Credentials:
• Juris Doctor, New York University School of Law, 2015 – Robert McKay Scholar, Senior Quorum Editor for the Journal of Legislation and Public Policy
• Summa Cum Laude, Brandeis University, B.A. in History and American Studies
Practice Areas:
• Data Breach Litigation
• Cybersecurity Litigation
• Consumer Litigation (TCPA)
• Securities Litigation
• Class Action Litigation
Awards:
• Recognized as “Ones to Watch” by Best Attorneys USA, 2021-2026
• Recognized as “Rising Star for New York Metro Area” by Super Lawyers, 2021-2024
Affiliations:
• Lieff Cabraser Heimann Kendrick LLP
• New York Bar Association
• New York City Bar Association
Contact Information:
City: New York, State: New York, Country: United States
