The legal battle between software developer Michael Lewellen and the United States Department of Justice (DOJ) has entered a critical new phase following the filing of a pivotal reply brief at the United States Court of Appeals for the Fifth Circuit. Lewellen’s ongoing lawsuit seeks to establish a definitive judicial boundary protecting creators of non-custodial cryptographic tools from criminal liability under federal money transmission statutes. At the heart of the dispute is 18 U.S.C. § 1960, a statute originally designed to target traditional, illicit unlicensed money-remitting businesses, which federal prosecutors have increasingly applied to decentralized finance (DeFi) software developers.
The latest court filing challenges a previous decision by a federal district court in the Northern District of Texas, which dismissed Lewellen’s pre-enforcement lawsuit. The lower court had concluded that Lewellen faced no credible threat of prosecution, heavily relying on a policy memorandum issued by then-Deputy Attorney General Todd Blanche. By pressing his case in the Fifth Circuit, Lewellen aims to secure a declaratory judgment affirming that the simple publication of open-source, non-custodial software does not constitute operating an unlicensed money-transmitting business. This legal confrontation occurs against a backdrop of legislative stagnation regarding blockchain regulation, leaving software architects to rely on federal courts to clarify their legal exposure.
Background and Chronology of the Dispute
The roots of Lewellen’s legal crusade trace back to a broader shift in federal enforcement strategies toward the cryptocurrency ecosystem. For years, government bodies such as the Financial Crimes Enforcement Network (FinCEN) maintained that the mere creation and publication of software did not constitute money transmission, drawing a clear line between technology developers and entities that maintain custody of user funds. According to established FinCEN guidance issued in 2019, an essential component of money transmission is the direct control or custody of customer assets.
Despite this regulatory framework, the DOJ has aggressively pursued criminal charges against developers of privacy-enhancing and decentralized protocols, most notably in high-profile enforcement actions involving Tornado Cash and Samourai Wallet. In these cases, federal prosecutors utilized expansive interpretations of 18 U.S.C. § 1960 to argue that writing and deploying code that facilitates peer-to-peer transactions or crowdfunding is legally equivalent to running a financial institution.
Faced with the prospect of criminal prosecution for developing "Pharos"—a non-custodial software application designed to streamline decentralized crowdfunding—Lewellen took the proactive step of filing a pre-enforcement challenge. Rather than waiting for federal agents to execute a search warrant or indict him, Lewellen sought a declaratory judgment to clarify his legal status. The Northern District of Texas dismissed the action, ruling that the plaintiff lacked standing because the DOJ had not explicitly targeted him with an investigation. Following the issuance of the Blanche memo regarding crypto enforcement priorities, the lower court determined the threat was speculative, prompting Lewellen to elevate the dispute to the Fifth Circuit.
Core Arguments Presented in the Fifth Circuit Reply Brief
Lewellen’s reply brief dismantles the government’s dismissal arguments through four primary legal pillars, focusing on standing, the expansion of prosecutorial overreach, the inadequacy of the Blanche memo, and the DOJ’s persistent refusal to formally disavow enforcement against non-custodial developers.
First, Lewellen defends his standing to sue preemptively. The DOJ argued that his fears are generalized because he has not been subjected to direct investigative actions. The brief counters that the entire purpose of a pre-enforcement declaratory judgment is to allow citizens to ascertain the legality of their conduct before risking felony prosecution and federal prison terms. Under appellate review standards, the Fifth Circuit must accept Lewellen’s technical descriptions of Pharos as true—specifically, that it operates entirely without user custody.
Second, Lewellen contends that the landmark prosecutions of Tornado Cash and Samourai Wallet validate his apprehension. The government argued that a law-abiding citizen should not fear prosecution if they are not engaging in identical criminal behavior. However, Lewellen points out that the DOJ’s strained statutory interpretation of 18 U.S.C. § 1960(b)(1) treats the mere creation of non-custodial tools as an unregistered money-transmitting business. Because the specific criminal charges under subsections (b)(1)(B) and (C) depend on the foundational premise that the defendant is engaged in "money transmitting" as defined by the statute, any developer publishing similar code falls directly into the crosshairs of the government’s overbroad reading.
Third, the brief addresses the government’s failure to explicitly disavow prosecution. While the DOJ has asserted in public statements that creating software is not inherently a crime, it has consistently refused to state that publishing non-custodial code without registering with FinCEN is legal under section 1960. By maintaining this ambiguous stance, the government preserves its latitude to bring charges at a later date, leaving developers in a state of perpetual legal jeopardy.
Fourth, Lewellen targets the district court’s reliance on the Blanche memo. Issued after the lawsuit commenced, the memo outlines internal prosecutorial priorities rather than altering the statutory interpretation of federal law. Furthermore, the memo explicitly permits prosecutions for willful failures to meet registration requirements, directly threatening developers who are aware that the government considers their software subject to FinCEN oversight.
Legislative Context and the Failure of Regulatory Reform
The urgency of Lewellen’s appeal is amplified by the failure of comprehensive legislative reform in the United States Congress. Proponents of digital asset innovation had placed significant hope in the Blockchain Regulatory Certainty Act (BRCA), which was introduced alongside broader regulatory packages such as the Clarity Act. The BRCA was intended to establish statutory safe harbors, shielding software developers and network operators from being misclassified as traditional money transmitters.
However, the legislative effort ultimately stalled, leaving the tech sector without statutory clarity. Legal analysts note that even if the most recent iteration of the BRCA had successfully passed, its protections were primarily focused on administrative registration rather than shielding developers from criminal statutes like 18 U.S.C. § 1960. Consequently, the burden of defining the legal boundaries of software development has fallen squarely onto the federal judiciary.
Implications for the Broader Technology Sector
The outcome of Lewellen’s appeal carries profound implications for the future of open-source software development, cryptographic research, and the broader tech industry within the United States. Legal scholars and civil liberties organizations warn that if the DOJ’s interpretation of section 1960 is permitted to stand, the chilling effect on software engineering could be catastrophic.
Classifying the publication of code as an act of financial transmission effectively criminalizes mathematics and software distribution. Because open-source tools are globally accessible, developers residing in the U.S. could be subjected to severe criminal penalties for publishing code that others might utilize for financial privacy or decentralized fundraising. This dynamic threatens to drive blockchain innovation and talent out of American jurisdictions into more favorable regulatory environments abroad.
As the Fifth Circuit deliberates on whether to reinstate Lewellen’s challenge, advocacy groups like Coin Center continue to back the litigation, framing it as a vital defense of constitutional rights and technological freedom. The court’s eventual ruling will not only determine Michael Lewellen’s professional fate but will also set a crucial binding precedent for how federal criminal statutes apply to the digital architecture of the twenty-first century.
