The operation, announced just before FBI Director Chris Wray addressed House lawmakers, disrupted a botnet of hundreds of U.S.-based small office and home routers owned by private citizens and companies that had been hijacked by the Chinese hackers to cover their tracks as they sowed the malware. Their ultimate targets included water treatment plants, the electrical grid and transportation systems across the United States.

Speaking before the House Select Committee on the Chinese Communist Party, Wray said there’s been far too little public focus on a cyber threat that affects “every American.”