U.S. Senator Elizabeth Warren has written to Commerce Secretary Howard Lutnick, requesting documents and communications related to Bitmain to understand how the Commerce Department handles potential national security risks posed by the company. Bitmain is a major global manufacturer of Bitcoin mining machines. In November 2024, the U.S. Department of Homeland Security launched an investigation codenamed "Operation Red Sunset" to examine whether Bitmain's ASIC miners could be remotely accessed for espionage or to interfere with the U.S. power grid. The investigation is reportedly still ongoing. Previously, shipments of Bitmain equipment were halted, and the use of its miners near U.S. military bases was flagged as a significant national security risk. Warren's letter also requests details of communications between Bitmain and the Trump family and Commerce Department officials. American Bitcoin Corp., backed by Trump, previously purchased 16,000 Bitmain mining machines for $314 million.