China Mobile has been asking for permission to expand its operations to the US since 2011 but has been stuck in limbo while intelligence agencies vet them. According to Pai, those investigations found that China Mobile poses "substantial and serious national security and law enforcement risks." Those concerns stem primarily from the belief that China Mobile is too cozy with the Chinese government and could help to spy on US citizens who use the company's networks and services.
The FCC and other government agencies have placed increased scrutiny on Chinese tech companies as of late, especially as those firms attempt to provide equipment to build out telecom networks. Following the passing of last year's Defense Authorization Act, US government employees and contractors can no longer use devices and technology from major Chinese tech makers Huawei and ZTE. The FCC has also explored barring US telecoms from purchasing network equipment from China-based firms.