The ongoing legal friction between software developers and federal law enforcement agencies reached a critical juncture this week as cryptocurrency developer Michael Lewellen filed his reply brief in the United States Court of Appeals for the Fifth Circuit. The legal challenge targets the Department of Justice’s interpretation of 18 U.S.C. § 1960, a federal criminal statute historically used to crack down on unlicensed money-transmitting businesses. Lewellen’s lawsuit contends that the DOJ’s broad and unprecedented reading of the law places him under an immediate and credible threat of criminal prosecution simply for publishing and operating "Pharos," a non-custodial cryptocurrency software designed to facilitate decentralized crowdfunding.
This high-stakes legal battle unfolds against a backdrop of increasing legislative uncertainty and aggressive federal enforcement actions targeting developers in the decentralized finance (DeFi) sector. With major regulatory protection bills, such as the Blockchain Regulatory Certainty Act (BRCA), having stalled in Congress, judicial intervention has become the primary mechanism for establishing legal boundaries between legitimate software development and illegal financial operations.
Background and Chronology of the Dispute
The genesis of Lewellen’s legal crusade traces back to his ambition to launch Pharos, a piece of software engineered to allow peer-to-peer, non-custodial financial interactions. In non-custodial architectures, users retain absolute ownership and control over their private keys and assets at all times; the software developer never takes possession, custody, or control of user funds. Under traditional regulatory frameworks—most notably the 2019 Guidance issued by the Financial Crimes Enforcement Network (FinCEN)—this distinction is paramount. FinCEN’s guidance explicitly states that the mere development of software, absent the custody or transmission of customer funds, does not constitute money transmission under federal law.
Despite FinCEN’s clear administrative boundaries, the Department of Justice has pursued an aggressive enforcement strategy over the last several years, most notably prosecuting developers associated with privacy-enhancing protocols and wallets such as Tornado Cash and Samourai Wallet. Observing these high-profile prosecutions, Lewellen opted for a proactive legal defense rather than waiting for federal agents to knock on his door. He filed a pre-enforcement challenge against the DOJ in the U.S. District Court for the Northern District of Texas. He sought a declaratory judgment confirming that publishing non-custodial software does not violate 18 U.S.C. § 1960.
The district court, however, dismissed Lewellen’s initial complaint. The dismissal was heavily influenced by a policy memo issued by then-Deputy Attorney General Todd Blanche, which outlined the DOJ’s discretionary enforcement priorities regarding cryptocurrency. The lower court reasoned that because of the Blanche memo, Lewellen faced no credible, imminent threat of prosecution, effectively closing the courthouse doors to his pre-enforcement challenge. Unwilling to accept a ruling that leaves open-source developers in legal limbo, Lewellen elevated the matter to the Fifth Circuit Court of Appeals, culminating in Monday’s comprehensive reply brief.
Core Arguments Presented in the Fifth Circuit Appeal
Lewellen’s latest legal filing dismantles the district court’s reliance on the Blanche memo and challenges the government’s standing arguments through four distinct legal pillars.
First, Lewellen addresses the threshold issue of judicial standing. The DOJ has repeatedly argued that Lewellen’s fear of prosecution is speculative and overly generalized because federal authorities have not initiated an investigation against him or issued a specific subpoena. Lewellen’s brief counters that this exact scenario—seeking judicial clarity before risking federal indictment—is the precise purpose of a pre-enforcement declaratory judgment. Under the rules governing this stage of litigation, the appellate court must accept Lewellen’s technical descriptions of how Pharos operates as true. Those descriptions establish that the DOJ’s interpretation of § 1960 classifies non-custodial software publishing as unlicensed money transmission, thereby establishing a legitimate fear of prosecution.
Second, Lewellen highlights how recent DOJ actions against other crypto projects substantiate his threat of prosecution. The government has attempted to argue that Lewellen cannot simultaneously claim to be a law-abiding citizen while maintaining a reasonable fear of criminal liability under § 1960. Lewellen’s attorneys push back, noting that the government frequently overreads criminal statutes. They point to the Samourai Wallet and Tornado Cash prosecutions, where the DOJ brought charges despite explicit warnings from FinCEN that the developers did not hold user assets. The DOJ’s willingness to bypass FinCEN’s administrative expertise demonstrates that adherence to non-custodial principles does not immunize a developer from federal overreach.
Third, the brief scrutinizes the government’s steadfast refusal to explicitly disavow prosecution. While the DOJ has asserted in legal filings that the mere creation and launching of software is not inherently a crime, it has carefully avoided clarifying whether publishing non-custodial tools without registering as a money-services business constitutes a violation under its reading of § 1960(b)(1). Without an explicit guarantee from prosecutors that building and releasing Pharos falls outside the scope of the statute, Lewellen remains exposed to severe criminal penalties, which can include substantial prison time.
Finally, Lewellen dissects the legal weight of the Blanche memo. The reply brief emphasizes that the memo merely outlines internal, discretionary enforcement priorities and was issued after Lewellen initiated his lawsuit. Consequently, it cannot retroactively cure the legal ambiguity or eliminate the underlying statutory threat. Furthermore, because the memo leaves intact the government’s authority to prosecute willful failures to register, it actually underscores the vulnerability of developers who know the government misinterprets their software as a regulated financial institution.
The Legislative Landscape and the Stalled Blockchain Regulatory Certainty Act
The urgency of Lewellen’s appeal is amplified by the current gridlock in Washington regarding digital asset regulation. The Blockchain Regulatory Certainty Act (BRCA), initially introduced as part of broader legislative packages like the Clarity Act, was designed to create a permanent statutory safe harbor for blockchain developers, miners, and node operators.
However, policy analysts and advocacy groups, such as the digital rights organization Coin Center, have noted structural limitations in previous iterations of the BRCA. While the proposed legislation would have clarified regulatory oversight under administrative bodies like FinCEN, it contained gaps regarding federal criminal statutes. Specifically, legal experts observed that previous drafts of the BRCA might have left developers vulnerable to prosecution under specific criminal subsections of 18 U.S.C. § 1960 that target unregistered operations.
Because federal legislation has failed to advance and historically left room for prosecutorial ambiguity, the burden of defining the rule of law has shifted decisively to the federal judiciary. If the Fifth Circuit rules in Lewellen’s favor, it could establish a vital binding precedent protecting open-source software developers across several states from executive overreach.
Implications for the U.S. Technology Sector
The implications of the Fifth Circuit’s eventual decision extend far beyond Michael Lewellen and the Pharos project. The case represents a fundamental test of whether open-source software—essentially mathematical code and published text—can be regulated or criminalized under statutes designed for traditional financial intermediaries like remittance companies and currency exchanges.
Legal observers note that if the DOJ’s interpretation of § 1960 is permitted to stand unchecked, a chilling effect will sweep across the American technology sector. Developers of decentralized applications, cryptographic tools, and privacy protocols could be forced to relocate outside the United States to avoid arbitrary felony prosecutions. Conversely, a victory for Lewellen would reinforce constitutional protections for speech and software publishing, reaffirming that writing code is a protected activity and that criminal liability under financial laws must be tethered to actual custody and control of user assets.
As the litigation proceeds in the Fifth Circuit, Coin Center and other civil liberties advocates continue to voice strong support for Lewellen’s legal team. The appellate court’s upcoming decisions on standing, prosecutorial disavowal, and statutory interpretation will likely shape the legal framework for blockchain innovation in the United States for years to come.
