The Federal Communications Commission on Thursday voted to revoke the ability of China Unicom Americas to offer telecom service in the U.S., the agency's latest crackdown on Chinese communication companies. Why it matters: The agency has reviewed several carriers' ties to the Chinese government and found they lead to unacceptable national security risks. Driving the news: The FCC said China Unicom Americas, as a U.S. subsidiary of a Chinese state-owned enterprise, is vulnerable to influence, exploitation and control by the Chinese government. The agency previously granted permission for the company to offer telecom services in the U.S. 20 years ago,...