The ongoing legal battle between software developer Michael Lewellen and the United States Department of Justice (DOJ) reached a critical juncture on Monday as Lewellen filed his formal reply brief in the U.S. Court of Appeals for the Fifth Circuit. The case centers on a pre-enforcement challenge against the government’s interpretation of 18 U.S.C. § 1960, a federal criminal statute prohibiting the operation of unlicensed money-transmitting businesses. Lewellen’s legal challenge seeks a declaratory judgment to protect creators of non-custodial cryptographic software from federal prosecution. The outcome of this appeal could establish a monumental legal precedent for open-source developers across the United States, particularly as legislative efforts to codify regulatory certainty for the blockchain industry stall in Congress.

Background and Genesis of the Dispute

The conflict began when Michael Lewellen sought legal clarity before publishing "Pharos," a non-custodial cryptocurrency software designed to facilitate decentralized crowdfunding. In the traditional financial sector, money transmission regulations heavily emphasize custody—meaning the direct holding and handling of customer funds. Under longstanding guidelines issued by the Financial Crimes Enforcement Network (FinCEN) in 2019, mere software development does not constitute money transmission, because developers of non-custodial tools never take possession or control of user assets.

Despite FinCEN’s explicit guidance, federal prosecutors have increasingly utilized 18 U.S.C. § 1960 to target creators of privacy-enhancing and decentralized tools. High-profile prosecutions, such as those against the developers of Tornado Cash and Samourai Wallet, signaled a aggressive shift in federal enforcement. In these cases, the DOJ argued that publishing decentralized applications and privacy tools equates to operating an unlicensed money-transmitting business if the software facilitates transactions between third parties, even when the creators have no custody over or access to the transacted funds.

Fearing that releasing Pharos would instantly expose him to felony charges under this expansive prosecutorial theory, Lewellen initiated a pre-enforcement challenge in the U.S. District Court for the Northern District of Texas. He requested a judicial declaration that publishing non-custodial code does not violate federal money transmission laws. However, the district court dismissed the lawsuit. The dismissal relied heavily on an internal policy memo issued by then-Deputy Attorney General Todd Blanche, which outlined DOJ enforcement priorities. The lower court ruled that the Blanche memo meant Lewellen did not face a credible, imminent threat of prosecution, effectively closing the courthouse doors before the core constitutional and statutory questions could be argued. This dismissal prompted Lewellen’s current appeal to the Fifth Circuit.

Chronology of Key Legal Filings and Policy Shifts

To understand the weight of Monday’s reply brief, it is essential to trace the chronology of events that have defined this litigation and broader cryptocurrency enforcement actions:

• May 2019: FinCEN publishes comprehensive guidance clarifying that developers who merely create software, without exercising custody or control over user funds, are not money transmitters under federal law.
• 2023–2024: The DOJ brings landmark criminal indictments against the developers of privacy mixer Tornado Cash and cryptocurrency mixing service Samourai Wallet, applying a broad reading of 18 U.S.C. § 1960 to non-custodial software creators.
• 2024 (Pre-enforcement Filing): Anticipating the public launch of his crowdfunding software Pharos, Michael Lewellen files a pre-enforcement declaratory judgment action against the DOJ in the Northern District of Texas to secure his legal standing as an independent developer.
• Late 2024 (The Blanche Memo): Following the initiation of Lewellen’s lawsuit, then-Deputy Attorney General Todd Blanche issues an internal memorandum detailing DOJ enforcement priorities regarding cryptocurrency.
• 2025 (District Court Dismissal): The Northern District of Texas dismisses Lewellen’s suit, accepting the government’s argument that the Blanche memo neutralizes any credible threat of prosecution.
• 2026 (Fifth Circuit Appeal): Lewellen files his initial appellant brief, followed by the DOJ’s response brief, culminating in Monday’s filing of Lewellen’s comprehensive reply brief in the U.S. Court of Appeals for the Fifth Circuit.

Core Legal Arguments Presented in the Reply Brief

In his Monday reply brief, Lewellen dismantles the DOJ’s defense through four primary legal arguments, challenging both the lower court’s reasoning and the government’s interpretation of federal criminal statutes.

First, Lewellen defends his legal standing to sue. The DOJ argued that his fear of prosecution is speculative and overly generalized because federal authorities have not yet launched a formal investigation against him or issued a specific subpoena. Lewellen’s brief counters that this logic defeats the entire purpose of a pre-enforcement challenge. Under established administrative and constitutional law, a citizen is not required to risk a federal felony conviction and potential imprisonment simply to test the boundaries of an overreaching government interpretation. At this procedural stage, the appellate court must accept Lewellen’s factual descriptions of how Pharos operates as true—meaning the DOJ’s stated positions inherently categorize his non-custodial software as an illegal money-transmitting business.

Second, Lewellen emphasizes that past and ongoing prosecutions against developers of tools like Tornado Cash and Samourai Wallet solidify the reality of his threat. The DOJ attempted to argue that Lewellen cannot simultaneously claim to be a law-abiding citizen and hold a reasonable fear of prosecution under the same statutory framework. Lewellen’s brief rejects this paradox, pointing out that the government frequently overreads criminal statutes. Because the DOJ’s charging strategy under 18 U.S.C. § 1960(b)(1) relies on the foundational premise that publishing functional software equals engaging in a money-transmitting business, any developer releasing open-source code falls directly into the government’s crosshairs.

Third, Lewellen addresses the DOJ’s persistent refusal to formally disavow prosecution. Despite reviewing the lawsuit, federal attorneys have declined to issue a clear assurance that publishing non-custodial software without registration is lawful. While the DOJ has asserted in public statements that "the mere creation and launching of software is not a crime," it simultaneously maintains that failing to register that software as a money-transmitting business is a criminal offense under its reading of the statute. Lewellen argues that without a concrete disavowal confirming that non-custodial code does not trigger money-transmission statutes, the legal peril remains entirely active.

Fourth, Lewellen targets the lower court’s reliance on the Blanche memo. The reply brief stresses that the memo is merely an internal policy document outlining prosecutorial discretion, not a formal change in statutory interpretation. Furthermore, because the memo was issued after Lewellen filed his initial lawsuit, it cannot retroactively eliminate his legal standing. Policy priorities can shift at a moment’s notice with changes in administration or leadership, leaving developers vulnerable to sudden shifts in enforcement posture unless federal courts establish firm statutory boundaries.

Legislative Stalemate Elevates Judicial Stakes

The urgency of Lewellen’s appeal is compounded by ongoing gridlock in the United States Congress. Proponents of digital asset innovation previously pinned their hopes on the Blockchain Regulatory Certainty Act (BRCA), which was introduced alongside broader legislative packages like the Clarity Act. The BRCA was designed to establish clear regulatory safe harbors for developers, miners, and non-custodial service providers, shielding them from overlapping state and federal money transmission licensing requirements.

However, the broader legislative push has faced severe hurdles, and even the most recent iterations of the BRCA contained critical limitations. Legal analysts, including policy researchers at digital rights advocacy group Coin Center, noted that previous versions of the BRCA were narrowly tailored to address regulatory compliance rather than criminal statutes. Specifically, while the BRCA might have offered relief from administrative registration penalties under subsections of 18 U.S.C. § 1960, it left ambiguities regarding subsection (C), which federal prosecutors have heavily relied upon to bring felony charges against developers.

Because legislative relief remains uncertain and incomplete, judicial intervention has become the primary line of defense for technology creators. Legal scholars observe that if the Fifth Circuit allows the district court’s dismissal to stand, it will create a chilling effect across the American technology sector. Software engineers could be effectively barred from publishing decentralized protocols, cryptographic wallets, and peer-to-peer applications without risking aggressive federal prosecution.

Broader Implications for Innovation and the Tech Sector

The implications of the Lewellen v. DOJ appeal extend far beyond the cryptocurrency ecosystem. The government’s novel interpretation of 18 U.S.C. § 1960 threatens the fundamental principles of open-source software development. Historically, the publication of source code has been fiercely protected under American law as a form of protected speech and scientific expression. By criminalizing the release of software based on how third parties might subsequently use it, the DOJ’s enforcement strategy blurs the line between software authorship and active financial intermediation.

Industry observers, civil liberties advocates, and technology associations are closely monitoring the Fifth Circuit proceedings. A ruling in favor of Lewellen would affirm the long-standing principle that criminal liability requires personal control, intent, and direct custody of funds—realigning DOJ enforcement with statutory definitions and FinCEN’s official guidance. Conversely, a victory for the government would institutionalize a broad prosecutorial discretion that could be expanded to target encryption tools, messaging applications, and general-purpose distributed computing networks.

As the appeal moves forward in the Fifth Circuit, Coin Center and other digital rights organizations continue to back Lewellen’s fight. The case now stands as a defining test of whether the American legal system will adapt to protect decentralization and technological innovation, or whether software developers must operate under the constant shadow of federal criminal liability for writing code.