There is new trend being done by China wherein it is making use of social media networks for the purpose of spying. Some of US intelligence officers have been regarded as guilty for spying for China. Read more at npr.org
It is difficult for Chinese intelligence officers to openly operate in the United States hence they approach contacts via social media platforms such as LinkedIn or any other platform.
Chinese intelligence officers are seen conducting their research regarding the people they want and once identified try and initiate contact with them.
The Chinese spies are increasingly seen to be spreading via students, researchers and business insiders.