How to control network spawn cameras?

Hi, I am having a problem with control networked cameras. I am creating a network game: Every player has a network spawned camera to observe scenes, and he can also observe scenes by using other players camera. Players will control transform of camera by using keyborad.I use Network Manager in my game. Everytime a player joins in, it will spawn a camera for this player. However, when a new camera object created, original camera which belongs to its owner can not function. Can anyone give some suggestions on how to manage networked camera? And how to synchronize cameras between players.