In a letter to top officials, Senators Elizabeth Warren and Angus King have raised concerns about potential national security threats posed by Iranian cryptocurrency miners. They called on the Biden administration to provide information regarding potential ties between the Iranian government and local crypto miners, and how digital assets might be utilised to bypass U.S. sanctions. Warren and King allege that Iran has utilised funds from crypto mining to support terrorist organisations and finance attacks, such as the April assault on Israel. The lawmakers have urged U.S. officials to furnish data on the revenue generated by crypto miners in Iran, its potential employment for money laundering, and strategies to address threats to national security. Reports indicate that Iranian Bitcoin miners may have amassed up to $1 billion in revenue in 2021, with the government allegedly favouring "newly-minted" Bitcoin due to its perceived lower traceability. While Iran has previously cracked down on crypto mining citing electricity concerns, it legalised the practice in 2019.