In China they have many large websites / search engines blocked for the use of their citizens such as Google. But seeing the value that Google presents the Government set up a nation wide system called CERNET (Chinese Education and Research Network) to allow students, teachers and researchers to access the resources Google can provide. In recent weeks students and teachers that use CERNET have reported that their searches have returned with errors such as “Invalid SSL certification”. The company in charge of CERNET’s security is called GreatFire. After they had shared their findings with another security based software company named Netresec, they concluded that these attacks are similar if not identical to the Man in the Middle attacks the Chinese government used on GitHub (A developer site) last winter. Upon looking into the mater with more detail they have found that the Chinese government was using these “MitM” attacks to get into the CERNET system and block “Harmful” search inquires.
Here is the article where I got my Information: