Tornado Cash (also stylized as TornadoCash) is an open source, non-custodial, fully decentralized cryptocurrency tumbler that runs on Ethereum Virtual Machine-compatible networks. It offers a service that mixes potentially identifiable or "tainted" cryptocurrency funds with others, so as to obscure the trail back to the fund's original source. This is a privacy tool used in EVM networks where all transactions are public by default. In August of 2022, the U.S. Department of the Treasury blacklisted the service, making it illegal for US citizens, residents and companies to use. The project's web domain and GitHub accounts were also shut down, and one of the developers arrested.