Cybersecurity & Data Privacy and White Collar Defense & Government Investigations


Guillermo Christensen advises clients on a range of enterprise risks involving the security of information systems and data ("cybersecurity") and insider threats to corporate assets and systems. He undertakes sensitive internal investigations for clients around allegations of foreign corruption, and violations of export controls and economic sanctions. In the national security law practice, he represents clients involved in securing approvals from the US Government for acquisitions of US businesses by foreign buyers. To all these areas, Guillermo brings a wealth of international business and government intelligence experiences to his practice, providing his clients with unique perspectives into troubleshooting complex and unusual problems.

Guillermo is a former CIA intelligence officer and a former diplomat with the U.S. State Department. He most recently served in a policy role as the Science and Technology Advisor to the U.S. Mission to the Organization for Economic Cooperation and Development (OECD) in Paris, where he led multi-stakeholder policy reviews of encryption, cybersecurity and cross-border data flows. From 2001-2002 he was the CIA Fellow to the Council on Foreign Relations in New York, an intelligence community position designated for officers on the cusp of the most senior responsibilities. From 2002-2004, Guillermo was on loan from the CIA to the FBI and to a national level counterterrorism intelligence fusion center to help improve intelligence collection and analysis of emerging threats.

As an attorney in private practice, Guillermo has worked on a variety of complex international investigations—including corruption and high-technology exports—and has represented clients in national security law matters, including vetting of sensitive transactions through the CFIUS process. He has experience with clients across the financial, technology, energy and defense sectors. In addition to his extensive international experience in the government, in private practice Guillermo has worked with clients in the Middle East, Latin America, Asia, Europe and Africa.

In the cybersecurity field, Guillermo has been a thought leader in discussions around intelligence collection, counter-measures, new business opportunities for emerging companies, and advising company boards and management. His focus has been on counseling clients in incorporating information security practices – based on his experience in the intelligence community – into their enterprise risk management and when breaches or insider threats are suspected, investigating and remediating the event. Drawing on this background, he recently helped draft the terms of reference for a Sedona Conference Working Group 11 project on Law Firms and Data Security and is currently involved in the next phase of that project.

Guillermo is active with several prominent organizations including as a life member of the Council on Foreign Relations. Born in Argentina, Guillermo is fluent in Spanish and has working knowledge of other languages.


Information Security

Assisted client with ransomware attacks on “family jewel” type assets

Negotiated with the U.S. Government following a breach in a sensitive defense related contract

Counseled a client after key systems were hijacked by hackers and posed a mission critical threat to their systems. Assisted the client in securing and recovering their assets

Trained energy clients at the staff and management level on assessing and scoping cybersecurity threats

Advised clients on intellectual property-related matters involving information security and associated systems

Counseled on cybersecurity dimensions of M&A transactions

Corporate Investigations and FCPA Compliance

Conducted yearlong internal investigation for a Fortune 100 high technology company in South America and Europe

Conducted an internal investigation in Colombia for a Fortune 100 company involving hiring practices and government officials

Conducted internal investigations and performed risk assessments relating to FCPA compliance, among the locations involved are Myanmar/Burma, Brunei, Chad, Saudi Arabia, Equatorial Guinea, Angola, Singapore, China, Russia, the UAE, Thailand, Malaysia, Mexico, Iraq, Egypt, Colombia and the UK

Fortune 500 oil services company – conducted acquisition due diligence on corporate target and post-closing diligence

Fortune 1000 company – consulted on enhancements to global anticorruption policies and procedures and training program

Russian telecommunications company – due diligence review in connection with planned acquisition of telecommunications company

Oil services company – drafted anticorruption policies and associated procedures and provided training to board, senior management and sales teams

Regulatory and National Security Law

Secured regulatory approvals including CFIUS for transaction involving weapons manufacturer

Leading global information and communications technology (ICT) solutions provider – advice and representation before CFIUS in connection with proposed U.S. investment activities

U.S. aviation maintenance and repair company – representation before CFIUS, State Department and Defense Security Service in connection with acquisition by AsiaPac purchaser

Secured CFIUS clearance by European aerospace company in a $1 billion acquisition of commercial and military aircraft business

International oilfield services company – comprehensive audit of export controls and sanctions compliance programs in connection with U.S. government investigation

Various multinational companies – regularly develop and oversee implementation of global export control and sanctions compliance programs

Large U.S. chemicals company – conducted comprehensive review of technology at all U.S. facilities to assess compliance with U.S. technology “deemed export” controls

International energy companies – advised on compliance with Crimea and Ukraine sanctions

Middle Eastern companies – counseled on compliance with U.S. Iran and Syria sanctions

International Arbitration and Complex Business Litigation

Sovereign state – arbitration of initial claims under a joint dispute board arising from a hydropower project

Represented the deposed head of a democratically elected government on a range of international legal matters

Represented petitioner before U.S. Supreme Court on statute of limitations appeal (BP Am. Prod. Co. v. Burton, 549 U.S. 84 (2006))


Georgetown University Law Center – J.D., cum laude, 2005
Georgetown University – M.S., Foreign Service, 1990
American University – B.A., International Relations, 1988

Bar Admissions

District of Columbia
New York
Speaking Engagements
Professional Affiliations
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Media Coverage