Sonja Arndt-Johnson is a Special Counsel in the Firm’s San Francisco office and a member of the Litigation (White Collar) practice group. Mrs. Arndt-Johnson has spent the past three years in private practice, originally joining private practice from the U.S. Department of Justice (U.S. DOJ) in Washington, D.C.  While at the U.S. DOJ, Mr. Arndt-Johnson worked at the U.S. Attorney’s Office for the District of Columbia, the Office of International Affairs (OIA), and the Computer Crimes and Intellectual Properly Section (CCIPS).

Mrs. Arndt-Johnson has extensive experience handling complex litigation matters, running internal investigations, mediating with private and government entities (i.e., DOJ, SEC, IRS, FTC, DOD, and OII with the IMF), managing public relations, and handling all phases of a case at both the state and federal levels, including having brought a dozen trials to verdict.  Mrs. Arndt-Johnson also has extensive experience working with small and large corporations on their data privacy policies and data breach response, including having completed a secondment at a Fortune 500 company.

Mrs. Arndt-Johnson’s client representations include but are not limited to combating fraud, money laundering, criminal RICO, CPRA/CCPA, BIPA, and wiretap allegations, investigating and bringing forth civil RICO claims, defending against extradition requests, managing internal corporate investigations, liaising with the Department of Defense regarding business and product classifications, among others.  Mrs. Arndt-Johnson also has experience drafting complex multi-jurisdictional privacy policies, terms of use and service agreements, DMCA policies, and prohibited content policies for starts-ups, small to mid-size corporations, and Fortune 500 companies.

Prior to practicing law, Mrs. Arndt-Johnson worked as a Congressional Aide on Military and Veteran Affairs, where she handled matters involving regulatory issues, investigations, legal compliance, and federal appropriations related to military, foreign aid, and international relations.

Ms. Arndt-Johnson is a strong advocate for zealous client representation having published on the issue with the American Bar Association (ABA) and partaken in the ABA’s podcast to discuss the importance of putting clients first.

Awards and Honors

  • Community Enhancement Award, Aptos Chamber of Commerce
  • S. Army Fort Hunter Liggett: Women’s History Month Keynote Speaker
  • 2014 Awardee, Disabled American Veterans, Chapter 85
  • CALI Award: Criminal Law Seminar, UC College of the Law, San Francisco (formerly UC Hastings)
  • Best Appellate Advocacy, UC College of the Law, San Francisco (formerly UC Hastings)
  • Chancellor’s Achievement Award for Diversity, UC Santa Cruz

Recent

  • Counsel for a lifestyle company, defending against a fraud prosecution in the Central District of California (Los Angeles), as well as a parallel SEC enforcement proceeding pending in the Southern District of New York (Manhattan).
  • Counsel representing the most prominent cryptocurrency tax case on record. The politically motivated charges concern tax evasion arising from bitcoin holdings prior to expatriation from the United States.
  • Counsel representing a Canadian encrypted phone and messaging provider and its CEO, who were indicted on charges of the Racketeer Influenced and Corrupt Organizations Act (RICO) violations and money laundering offenses stemming from the sale of encrypted phones, with revenues allegedly exceeding $100 million.
  • Counsel representing one of the largest PVC-pipe manufacturers in the U.S. in connection with a RICO and fraud lawsuit for sham claims asserted by one of the largest plaintiff’s asbestos law firms in the U.S.
  • Counsel for a medical practice group and certain affiliated owners in one of the largest California-based healthcare qui tam lawsuits involving personal injury medical lien-based services and procedures pursued by State Farm in 2024. Investigated and resolved litigation against all clients within 90 days with a complete release of liability for all clients.

White-Collar

  • Counsel for a Texas oil investor facing wire fraud allegations.
  • Counsel for a San Francisco businessman facing wire fraud allegations in relation to an alleged political corruption kickback scheme.
  • Counsel for a group of California businessmen facing international import crimes and related fraud allegations.
  • Counsel for a CEO facing fraud allegations by the Office of Institutional Integrity (OII).

Investigations

  • Counsel for companies facing California Greenwashing Taskforce investigations.
  • Counsel for Chinese-based companies facing Department of Defense (DoD) and Department of Justice (DoJ) investigations.
  • Counsel for for-profit and non-profit clients facing FTC investigations and related discovery requests.

Class Actions

  • Counsel for a retail client facing an Unlawful Trade Practice Act (UTPA) class action before the Oregon Supreme Court.
  • Counsel for a corporation facing an ERISA class action before the Second Circuit.
  • Counsel for a university facing a Title IX class action in San Francisco.
  • Counsel for a retail client in summary judgment proceedings related to a Washington Consumer Protection Act (CPA) class action.
  • Counsel for multiple corporate clients having class action lawsuits in relation to wiretap claims as it relates to Chatbots and session replay software.

Judgement Enforcement

  • Counsel for a Korean-based client on an arbitration clause enforcement issue.
  • Counsel for a corporation client facing a judgment enforcement demand in relation to a commodities fraud allegation involving Bitcoin.

Other Experience

  • Counsel for a telecommunications company for an emergency cease and desist request in relation to state wiretap violations.
  • Secondee at Airbnb working on legal policy matters.
  • Counsel for multiple retail clients on multi-state data breach reporting and notification compliance, federal health breach notification compliance, and contractual obligations under the Payment Card Industry (PCI) guidelines.

Ms. Arndt-Johnson earned her J.D. from the University of California College of the Law, San Francisco (formerly UC Hastings) where she was Editor in Chief of the Hastings Women’s Law Journal. She earned her B.A. in Business Management Economics and Politics from the University of California, Santa Cruz.

  • California
  • United States District Court, Northern District of California
  • United States District Court, Central District of California
  • United States District Court, District of Columbia
  • Team Leader, Human Race (Santa Cruz County Animal Shelter)
  • Volunteer, Native Animal Rescue of Santa Cruz County
  • Volunteer, Grateful Dogs Rescue
  • Volunteer, Cross-Cultural Solutions (Thailand and Tanzania)
  • Volunteer, Santa Cruz County Animal Shelter
  • Founder, UC Santa Cruz Global Microfinance Brigades (Honduras)