Revisiting the Letter of Marque: Leveraging the Private Sector in Offensive Cyberspace Operations - An Analytical Reflection on Historical Analogies and Contemporary Policy Debates

1. Executive Summary

This policy brief explores a structured model for state-authorized private sector engagement in offensive cyberspace operations. The idea draws inspiration from the historical concept of the letter of marque, which allowed states to authorize private actors to disrupt enemy assets under legal protection. While the 18th-century practice is not directly applicable today, it offers a useful model for assigning limited, accountable roles to private cybersecurity firms in support of national objectives. The brief uses Operation Glowing Symphony—a coordinated U.S. Cyber Command operation targeting ISIS media infrastructure—as a case study. It demonstrates how state-led offensive operations can be developed, rehearsed, and executed in a way that maintains legal oversight and operational discipline. Rather than opening the domain to unregulated hacking, the exploration focuses on enabling authorized and bounded actions against specific non-state threat actors operating below the threshold of armed conflict.

The model includes time-bound mandates, legal immunity under strict conditions, and mandatory coordination with national agencies. This approach can enhance national resilience and deterrence capacity without expanding permanent state structures. It also offers a practical response to concerns over asymmetric threats from actors with greater scale and coordination than many states can counter alone.

2. Problem Statement

States face growing pressure to respond to persistent cyberspace operations conducted by both state and non-state actors. These operations often target critical infrastructure, financial networks, and information systems. Traditional defensive measures, while necessary, have not been sufficient to reduce the frequency or severity of such threats. At the same time, there is a significant gap between national cyber capacity and the capabilities of adversaries. For example, according to Nextgov, the U.S. has acknowledged being outnumbered in cybersecurity personnel compared to China by a factor of 50 to 1. In this environment, private sector expertise is both more advanced and more scalable than what is currently available within government structures.

However, no formal framework exists to allow private firms to contribute to offensive operations in a legally sanctioned and coordinated manner. Without such a framework, ad hoc actions risk undermining ongoing intelligence work, triggering diplomatic tensions, or creating legal uncertainties. The absence of an accountable model for private sector participation in offensive cyberspace responses may limit the state’s ability to act in grey-zone competition or conflict. A structured, state-authorized mechanism may offer a way to bridge this gap and to guide private action under law, oversight, and clear operational limits.

3. Background & Analogy

The concept of a letter of marque originates from maritime law. It was used by states to authorize private vessels to attack and seize enemy ships during wartime. These letters allowed governments to expand their reach without deploying additional naval forces, while also maintaining legal oversight and accountability through courts of admiralty. While this historical mechanism is no longer in use, it offers a useful analogy for structured private participation in offensive cyberspace operations. In both contexts, the state faces a resource gap and must find ways to extend its reach through regulated non-state actors.

In cyber policy discussions, the idea has resurfaced as a metaphor for how private firms might be legally authorized to act against threats such as ransomware groups or transnational cybercriminals. The goal is not to replicate 18th-century practices but to draw lessons about how states can responsibly delegate certain functions under clear legal and operational frameworks. A modern precedent exists in Operation Glowing Symphony (OGS)—a U.S. Cyber Command-led mission to disrupt ISIS’s media operations. OGS was structured, rehearsed, and legally authorized. It demonstrates how a state can conduct offensive cyberspace operations without relying solely on kinetic force or open warfare.

Table 1 illustrates the conceptual similarities between historical maritime practice and this modern cyber operation.

Table 1: Comparison of historical and contemporary State-authorized disruption models

This table supports the brief’s central analogy and highlights the relevance of structured state delegation in contemporary cyber strategy.

4. Policy Proposal

This brief outlines a potential framework that allows vetted private sector actors to carry out time-limited, targeted offensive cyberspace operations under legal oversight. The framework is inspired by historical state practices (letters of marque) and informed by the operational experience of Operation Glowing Symphony.

The model includes the following components:

A. Legal Authorization
Private actors would operate under a formal legal instrument—such as an executive order, legislative provision, or defense authorization. The authorization would define the operation’s scope, time frame, geographic focus, and targets (e.g., non-state threat actors).

B. Eligibility and Oversight
Only pre-vetted private entities—with existing clearances, contractual ties to government, and operational maturity—would qualify. All operations must be pre-approved, monitored, and deconflicted with agencies such as USCYBERCOM, NSA, DHS, or DOJ. Operators must follow rules-of-engagement approved by legal and technical authorities.

C. Operational Limits
All actions must be non-kinetic, focused on disruption or degradation of non-state threat actors’ digital capabilities. Operations must avoid causing direct, disproportionate, or sustained disruption to civilian services or critical infrastructure not being used for hostile purposes.

D. Legal Protections
Participating firms could receive limited liability protections, akin to those provided under the 2015 Cybersecurity Information Sharing Act (CISA), provided their actions comply with formal authorization and oversight requirements. A transparency and review mechanism should be established to monitor outcomes and ensure lawful execution.

Table 2 compares the key attributes of Operation Glowing Symphony with the proposed framework, highlighting how similar principles of authorization, coordination, and legal constraint can be applied to qualified private sector actors in future operations.

Table 2: Comparison between Operation Glowing Symphony and the proposed private-sector offensive cyber framework

Such a model could help expand national capacity while maintaining legal control and operational discipline.

5. Addressing Key Concerns

The idea of authorizing private actors to conduct offensive cyberspace operations raises valid concerns. These concerns must be addressed through clear legal mandates, operational oversight, and built-in limitations. One concern is that such actions could be misused or lead to escalation. To avoid this, the proposed framework limits operations to non-state targets and requires pre-authorization, coordination, and oversight by national authorities. Actions must also follow strict rules of engagement and remain within legally defined boundaries.

Another concern is the disruption of intelligence collection or interference with military operations. This is addressed through mandatory deconfliction, as demonstrated in Operation Glowing Symphony, where Cyber Command coordinated actions across agencies to avoid operational overlap.

Legal ambiguity is also a common issue. By integrating liability protections and authorization mechanisms similar to existing frameworks (e.g., CISA), this proposal provides a structured legal environment that distinguishes it from unsanctioned so-called “hack-back activity.”

Finally, the concern that civilian infrastructure could be unintentionally affected is mitigated through the requirement to avoid direct, disproportionate, or sustained disruption to systems not used for hostile purposes.

Table 3 summarizes these concerns alongside the proposed mitigation mechanisms, showing how the framework maintains legal clarity and operational restraint.

Table 3: Key policy concerns and corresponding mitigation measures

These measures are designed to help reduce the risk that the framework undermines legal norms or operational stability while supporting state objectives.

6. Use Case Prioritization

This framework is not envisioned for use in inter-state armed conflict or against state-controlled military systems. It applies to non-state threat actors operating below the threshold of war, including in active conflict zones, where operations support counterterrorism, counter-crime, or digital stabilization objectives.

Priority targets may include non-state threat actors engaged in disruptive or harmful activities, illicit online platforms, terrorist media outlets disseminating propaganda, and botnet operators undermining essential services. Operations under such a framework could aim to disrupt functionality, seize data, or temporarily deny access to digital infrastructure, while avoiding broader or sustained collateral effects. Table 4 provides examples of eligible and excluded targets, offering a structured approach to prioritization that reflects both legal boundaries and operational discretion. Operations could focus on disruption, data seizure, or temporary denial of digital capabilities, with minimal collateral effects.

Table 4: Target selection parameters for private-sector offensive cyberspace operations

This prioritization supports strategic coherence, aligns with legal boundaries, and maintains operational restraint.

7. Strategic Benefits

This framework could offer a way to increase national cyber capacity without expanding permanent government structures. By enabling temporary, state-authorized private sector operations, the state can respond more flexibly to time-sensitive threats.

It also supports targeted disruption of adversary networks, which raises operational costs for threat actors and can reduce the frequency or persistence of hostile activity. Importantly, it provides a legal and coordinated alternative to unsanctioned hack-back practices, which risk undermining intelligence efforts and international norms. Table 5 summarizes how the proposed model addresses current limitations in national cyber response capacity, offering structured and lawful enhancements without compromising oversight or strategy.

Table 5: Addressing limitations in current cyber response models

The approach supports resilience, burden-sharing, and a more proactive cybersecurity posture.

8. Recommendations

To explore the viability of this approach, a pilot could be tested through a limited pilot program administered by, for example, either the Department of Defense or the Department of Homeland Security. This pilot could focus on non-state threat actors engaged in disruptive or harmful activities or counter-terrorism operations targeting non-state actors, allowing for the evaluation of legal, technical, and operational procedures in practice.

To support such a pilot, the government could issue a formal legal instrument—either an executive order or a legislative provision—that authorizes time-bound, state-sanctioned offensive cyber activities by designated private entities. Participation could be limited to firms with prior security clearances, demonstrated technical capability, and a history of regulatory compliance.

Oversight must be managed through an interagency review process involving legal, operational, and diplomatic input. This process could be designed to ensure that all activities remain aligned with national law, avoid strategic miscalculation, and support broader policy objectives. These steps can enable a controlled and accountable expansion of national cyber capabilities.

9. Conclusions

Expanding national cyber capacity through a structured, legally grounded framework for private sector engagement offers a realistic way to address growing operational demands. Drawing on historical analogies and operational lessons, such as Operation Glowing Symphony, the proposal outlines how state-authorized private actions can be integrated into national strategy without undermining legal or strategic norms. By focusing on non-state threats and embedding oversight into every stage, this approach enables measured use of existing expertise while maintaining public accountability. It may represent a step toward more adaptive and coordinated responses to emerging threats in cyberspace.

Disclaimer: The views expressed in this policy brief are solely those of the author and do not reflect the official positions of any current or past affiliated organizations. All references and case examples are used for illustrative and analytical purposes only.