No military personnel
On top of all the other strange and unusual rules that the Chinese state has with censoring the internet, they even prevent some people from using it together. If you are in the Chinese military, depending on your rank, you are not allowed to be on the internet at all alone.
The government is worried that you may be tricked into giving up secrets or even spreading information about the military to others. So basically they want everyone who is in uniform to keep their lips sealed when it comes to what they are doing behind the scenes. So much for internet dating.