People walk past a PCCW sign in Hong Kong.Mike Clarke | AFP | Getty Images Regulators in the U.S. have moved to block one of Hong Kong's largest telecommunications companies from accessing domestic networks, citing national security concerns.The U.S. Federal Communications Commission announced on Wednesday that it had initiated proceedings to potentially bar HKT Trust and HKT Ltd and its subsidiaries from interconnecting with American networks, escalating concerns over its ties to China. The gov...