Diana M. Feinstein is a partner in the Century City office of Gibson, Dunn & Crutcher. She is a member of the firm’s White Collar Defense and Investigations, Litigation, and Class Actions Practice Groups.
Diana’s practice centers on white collar defense and investigations, with a particular emphasis on complex internal investigations and enforcement matters brought by the Department of Justice, Securities and Exchange Commission, Consumer Financial Protection Bureau and Federal Trade Commission. She regularly advises companies, boards and senior executives in high-stakes matters involving criminal, civil and regulatory exposure.
In recognition of her work, Diana has been selected by her peers for inclusion in The Best Lawyers in America® in the field of Criminal Defense: White Collar. In addition to her investigations practice, she represents clients in complex litigation, including consumer class actions, securities disputes and high-value commercial litigation.
Diana’s experience spans a wide range of industries, including technology, financial services, entertainment, insurance, healthcare, transportation, real estate, manufacturing and consumer products. Drawing on her dual investigations and litigation practice, she has deep expertise navigating parallel proceedings involving criminal, civil and regulatory components, particularly in crisis-driven matters where early strategic decision-making is critical.
She also has significant experience managing electronic discovery and digital forensics, which frequently play a central role in large-scale investigations and complex disputes. Diana is a frequent speaker on issues such as attorney-client privilege, parallel proceedings and electronic discovery.
Diana earned her Juris Doctor from Georgetown University Law Center in 2007. She graduated summa cum laude from the University of Pennsylvania in 2004, receiving a Bachelor of Arts in History. She currently serves as Co-Chair of the Legal Network for the Jewish Federation Los Angeles and previously served on the Board of the Western Center on Law & Poverty.
Diana is admitted to practice in California and New York.
Representative Internal Investigation and Government Enforcement Defense Experience
- Representing global franchisor in investigations by the Securities and Exchange Commission, Department of Justice, Federal Trade Commission, and several State Attorney General Offices, as well as parallel civil litigation.
- Conducted internal investigation on behalf of special committee of independent directors of a pharmaceutical company regarding allegations of executive misconduct.
- Conducted internal investigation on behalf of special committee of independent directors of international gaming company regarding adequacy of internal controls.
- Conducted internal investigation on behalf of the board of directors of a global nutrition and supplement company regarding anti-money laundering controls.
- Conducted internal investigation for global data storage company regarding intellectual property issues.
- Conducted internal investigation for global retailer regarding product compliance and trade control issues.
- Represented top social networking company in investigation by the Consumer Financial Protection Bureau.
- Representing climate finance company and board member in investigations by the Securities and Exchange Commission, Department of Justice, and Commodity Futures Trading Commission.
- Represented technology company in investigations by the Securities and Exchange Commission and Department of Justice stemming from IPO disclosures, resulting in declinations from both government regulators.
- Represented international bank in nonpublic investigation by Department of Justice and United States Attorney’s Office for alleged violations of anti-money laundering laws and regulations, including the Bank Secrecy Act.
- Represented international gaming company in nonpublic investigation by Department of Justice and United States Attorney’s Office for alleged violations of anti-money laundering laws and regulations, including the Bank Secrecy Act.
- Represented investment management firm in connection with various regulatory and criminal investigations arising from trades in mortgage-backed securities.
Representative Civil Litigation Experience
Technology, Privacy & IP Litigation
- Representing a leading social networking company in litigation alleging violations of Illinois’s Biometric Information Privacy Act (BIPA).
- Successfully represented Archer Aviation, a leading eVTOL aircraft company, in trade secret litigation and the prosecution of defamation counterclaims, securing key victories including defeat of a preliminary injunction motion, significant narrowing of claims at summary judgment, and defeat of the plaintiff’s summary judgment motion.
- Defended a major technology manufacturer in nationwide multidistrict litigation (MDL 2827), obtaining early dismissal with prejudice of all statutory and common law fraud claims.
Mass Actions & Complex Employment Litigation
- Obtained decertification of a class of more than 11,000 J.B. Hunt truck drivers on the eve of trial in a long-running wage and hour action.
- Defended the University of Southern California in coordinated mass action litigation arising from alleged employee misconduct, including parallel civil litigations and regulatory investigations.
Toxic Tort & Large-Scale Discovery
- Coordinated extensive discovery and managed damages experts in the defense of a mass toxic tort action brought by more than 400 former workers against an international engineering firm.
Securities & Financial Litigation
- Secured a rare reversal by the New York Appellate Division of a denial of summary judgment on behalf of Trust Company of the West (TCW), establishing that alleged losses were caused by the financial crisis rather than management conduct.
- Obtained voluntary dismissal with prejudice of a putative securities class action concerning foreign exchange practices on behalf of multiple global financial institutions and underwriters.
Capabilities
- White Collar Defense and Investigations
- Anti-Money Laundering
- Betting and Gaming
- Class Actions
- Consumer Protection
- Crisis Management
- Intellectual Property
- Labor and Employment
- Litigation
- Product Liability
- Securities Litigation
- Technology Litigation
Credentials
Education:
- Georgetown University - 2007 Juris Doctor
- University of Pennsylvania - 2004 Bachelor of Arts
Admissions:
- California Bar
- New York Bar