Sen. Elizabeth Warren has asked the U.S. Commerce Department to disclose how it is addressing potential national security risks tied to Bitmain, the Chinese maker of a large share of the world’s Bitcoin mining equipment, Bloomberg reported. In a letter to Commerce Secretary Howard Lutnick, sent Thursday, Warren sought documents and communications related to the company.
U.S. authorities reportedly opened a probe last November — dubbed “Operation Red Sunset” and led by the Department of Homeland Security — to assess whether Bitmain’s ASIC machines could be accessed remotely for espionage or used to disrupt the U.S. power grid. Bloomberg says that probe remains unresolved and its current status is unclear; such national security investigations can continue for years without public disclosure or legal action.
The renewed scrutiny follows earlier federal actions, including halted shipments of Bitmain devices and a separate inquiry into a related Chinese chip firm over alleged ties to sanctioned Huawei. A 2024 federal review also flagged the use of Bitmain machines near a U.S. military base as raising “significant national security concerns.” Bitmain has also reportedly been preparing to open its first U.S.-based ASIC manufacturing facility, with chip production expected to begin in early 2026 and scale through the year.
Bitmain’s mining rigs are widely used, including by American Bitcoin Corp., which counts Eric Trump and Donald Trump Jr. among its investors. That firm agreed last year to buy 16,000 Bitmain rigs in a $314 million deal. Warren’s letter asks for any communications between Bitmain, the Trump family and Commerce officials, and requests information on what measures the department has taken to insulate national security decisions from political influence.
Cointelegraph contacted Warren and Bitmain for comment but had not received responses by publication.