plaintiff Van Loon appealed on September 2nd in the Fifth Circuit Court, challenging the US Treasury Department's decision to list Tornado Cash as a specially designated national (SDN). The plaintiff believes that the Treasury Department's sanctions on this open source project without clear guidance may threaten the First Amendment rights of programmers.

Van Loon and his team sued the Treasury Department in September 2023, accusing it of exceeding its powers. Tornado Cash was sanctioned for alleged money laundering activities, and the government claims that the platform has been involved in more than $7 billion in illegal funds since 2019. The Electronic Frontier Foundation (EFF) supports this lawsuit, fearing that government sanctions will have a chilling effect on open source software development.

Previously, the district court dismissed the lawsuit, stating that sanctions were limited to transactions involving the Tornado Cash smart contract and did not affect the development and discussion of open source code. However, the EFF and other digital rights advocates remain concerned about the wide-ranging impact of the case, emphasizing the importance of protecting the rights of programmers.