Bitmain, a privately held Chinese company, controls an estimated 80% of the global market for cryptocurrency mining hardware. The application-specific integrated circuits it manufactures — the ASICs that power the overwhelming majority of Bitcoin mining operations worldwide — are physically present inside data centers scattered across the United States, operating at sustained high power loads, networked to the internet, and in many cases located in states with significant military or defense infrastructure. In November 2025, the Department of Homeland Security opened a formal investigation into whether Bitmain’s equipment can be remotely controlled for surveillance, espionage, or grid disruption purposes.