Roman Storm, co-founder of Tornado Cash, is facing trial on July 14 for money laundering and operating an unlicensed money transmitter.
Tornado Cash is a cryptocurrency-mixing service allowing increased privacy but has been used by hackers to launder money.
The Ethereum Foundation supports Storm, advocating for privacy and defending the role of developers in the DeFi market.
US authorities allege Tornado Cash laundered over $1 billion in illicit funds, enabling criminals to disguise transactions.
The case against Storm signifies a change in US crypto regulation, following a scaling back of regulatory activities.
Storm's defence argues the case threatens open source innovation and could harm the DeFi market.
The DOJ sought Storm to implement KYC procedures with Tornado Cash, which he believes would render the service obsolete.
Storm faces challenges in presenting expert witnesses during his trial, with the DOJ dismissing their relevance to the case.
The Ethereum Foundation donated funds for Storm's defence, stating their belief in his innocence and the importance of privacy technologies.
A hacker who stole $23 million in crypto from Bittrue exchange in 2023 is laundering the funds through Tornado Cash, potentially complicating the case.