What is the fine-grained topic of the following text: As JTA notes, the 2010 letter he signed on to said: "We are very concerned that these companies are being financed by the Chinese government and are potentially subject to significant influence by the Chinese military which may create an opportunity for manipulation of switches, routers, or software embedded in American telecommunications network so that communications can be disrupted, intercepted, tampered with, or purposely misrouted." Only return the topic.
Concerns about Chinese government's influence on American telecommunications network