Overview

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Sonja Arndt-Johnson is Special Counsel in the Firm’s San Francisco office and a member of the Litigation (White Collar) and Privacy & Data Security practice groups. She brings more than four years of private practice experience, following her tenure with the U.S. Department of Justice (DoJ) in Washington, D.C. While at the DoJ, Mrs. Arndt-Johnson served in the U.S. Attorney’s Office for the District of Columbia, the Office of International Affairs (OIA), and the Computer Crime and Intellectual Property Section (CCIPS). Prior to joining the DoJ, Mrs. Arndt-Johnson was a line prosecutor at Santa Clara County District Attorney’s Office.

Mrs. Arndt-Johnson is an efficient litigator who moves thoroughly and quickly through investigations, providing quick resolutions for civil and criminal matters.  She has extensive experience handling complex litigation, conducting internal investigations, and navigating high-stakes negotiations with both private and government entities—including the DoJ, SEC, IRS, FTC, DoD, CA State AG, local CA district attorney offices, and the IMF’s Office of Internal Investigations. She has managed public-facing crisis communications and overseen all phases of state and federal cases, bringing more than a dozen trials to verdict. She also advises companies of all sizes on data privacy compliance and breach response, and previously completed a secondment at a Fortune 500 company. Having represented dozens of individuals and corporations in matters involving fraud, money laundering, qui tam actions (including, but not limited to, the corporate practice of medicine and kickbacks allegations), criminal and civil RICO, CPRA/CCPA, BIPA, and wiretap allegations, Mrs. Arndt-Johnson is a straight shooter who fights for her clients.

Prior to practicing law, Mrs. Arndt-Johnson advised members of the U.S. Senate and House of Representations on military, veteran, and foreign affairs. Prior to working for Congress, Mrs. Arndt-Johnson managed community outreach for Presidential and Congressional elections and ran a non-profit organization in Central America.  

Recent

  • Lead Counsel for an officer of a medical facility in a state criminal action alleging healthcare fraud and money laundering related to COVID-19 billing with damages allegedly exceeding $45 million.
  • 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 Pledge Medical, LLC, 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 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 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 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.
  • 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.

Admissions

  • California
  • U.S. District Court for the Northern District of California
  • U.S. District Court for the Central District of California
  • U.S. District Court for the District of Columbia

Education

  • University of California College of the Law, San Francisco, J.D.
    • Editor in Chief of the Hastings Women’s Law Journal
  • University of California, Santa Cruz, B.A., Business Management Economics and Politics

  • 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
  • Chancellor’s Achievement Award for Diversity, University of California, Santa Cruz

  • Board Member and Vice President, Privacy & Data Security, HR Executive Compliant Council
  • Member, The Bar Association of San Francisco: BASF
  • Member, Women’s White Collar Defense Association
  • Member, National Association of Criminal Defense Lawyers

 

 

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