Well I think when you have 1 bar it is a problem of your internet connection, Treyarch/Activision has nothing to do with it.
This happens to me a lot, when someone in home is using the internet (besides me) I get 1 red bar... You should check if someone is downloading something while you are playing, or someone might be stealing your connection.
Firstly, 7 people in the same game isn't a coincidence is guess. I contacted my ISP, done everything i could. Nothing helped.
And, my internet is password encrypted lol.. I live in the ghetto, everyone near my apartment isn't that well-educated..
When i play my games, other than my sister using her computer, no one should be downloading anything. I don't download random stuffs on the internet.