US Prosecutors Move to Block Tornado Cash Founder’s Expert Witnesses as Legal Battle Intensifies

On June 13, Protos reported that U.S. prosecutors have filed a motion to prevent expert witnesses from testifying on behalf of Tornado Cash founder Roman Storm, arguing that their testimonies would “waste jury time” and “confuse” jurors on matters related to privacy, token economics, and know-your-customer (KYC) regulations. With Storm’s trial set to begin in less than 30 days, the case has taken significant turns, including the Department of Justice (DOJ) dropping the “unlicensed money transmission” charge while retaining money laundering allegations. Notably, prosecutors have also ceased referring to Tornado Cash as a “financial institution.” Storm has warned that a loss in this case could have dire implications for decentralized finance (DeFi), stating, “If I lose, DeFi dies with me. The dream of financial freedom, the code I believed in — it all fades into darkness.”

The Ethereum Foundation has stepped in with substantial support, announcing on June 14 that it will provide $500,000 for Storm’s legal defense and match up to $750,000 in community donations, emphasizing that “privacy is normal, and writing code is not a crime.” This financial backing comes at a critical time, as Storm has previously indicated on social media that his legal funds were running low.

Case Background and Recent Developments

Tornado Cash, a non-custodial Ethereum-based privacy protocol, allows users to obfuscate transaction details on the blockchain, raising concerns among regulators about its potential use for illicit activities. Roman Storm, along with co-developer Alexey Pertsev, faced legal scrutiny following the U.S. Treasury’s Office of Foreign Assets Control (OFAC) sanctioning Tornado Cash in August 2022 for allegedly facilitating money laundering, including by North Korean hackers. However, in March 2025, OFAC lifted these sanctions, and a Fifth Circuit ruling found the Treasury’s actions had overstepped its authority, marking a partial victory for the protocol.

Storm’s legal team has faced mounting challenges. In September 2024, motions to dismiss the case were denied, setting the stage for the upcoming trial on July 14. The defense has argued that prosecuting Storm for writing open-source code threatens free speech and innovation, a stance supported by the Electronic Frontier Foundation (EFF) in an amicus brief filed in January. However, the DOJ responded that its prosecution is unrelated to whether Tornado Cash’s computer code constitutes free speech or is protected under the First Amendment.“The defendant is not being prosecuted for posting computer code,” claimed the DoJ. “Instead, he is being prosecuted for his use of it in furtherance of a profitable and illicit business.”

The prosecution’s latest motion to exclude expert witnesses claims their testimony would introduce irrelevant or overly complex information, potentially muddling the jury’s understanding of the charges. This move has drawn criticism from privacy advocates, who argue that the government is attempting to limit the defense’s ability to contextualize Tornado Cash’s technology and its role in DeFi.

Community and Industry Support

The crypto community has rallied behind Storm, with prominent figures and organizations voicing support. Ethereum co-founder Vitalik Buterin has donated three times to support Storm’s legal defense and has repeatedly posted on X to emphasize the value of privacy.

Paradigm, a crypto venture capital firm, also donated $1.25 million in January, highlighting the case’s broader implications for open-source development.

Implications for DeFi and Privacy Tools

The Tornado Cash case is widely seen as a litmus test for the future of privacy-focused protocols and DeFi. Unlike centralized platforms, Tornado Cash operates without intermediaries, raising novel legal questions about developer liability for decentralized systems. The DOJ’s decision to drop the “financial institution” label and the unlicensed money transmission charge suggests a recalibration of its approach, possibly in response to earlier court rulings. However, the retained money laundering charges indicate that regulators remain focused on curbing the protocol’s alleged misuse.

The Ethereum Foundation’s financial commitment and the community’s response reflect growing concern about the chilling effect a conviction could have on developers. The Foundation’s statement reinforces the view that privacy tools serve legitimate purposes, such as protecting users from surveillance or financial censorship.

Looking Ahead

With the trial approaching, Storm’s legal team has requested an extension to counter the prosecution’s motion to exclude witnesses, a request bolstered by the Ethereum Foundation’s funding. The outcome of this case could shape the regulatory landscape for DeFi and privacy tools, determining whether developers can be held liable for how their code is used.