Sometimes, you want to be able to see the channels for all the objects when working on one. There is a button that will let you display the F-Curves for all visible objects:
In 3D View, click on Camera with the RMB.
In the Graph Editor header, there is an arrow button that is highlighted in the next screenshot. Click on it with the LMB.
Do it several times and watch Graph Editor and the Channel Selection Panel.
The arrow button toggles between whether only the F-Curves related to the currently-selected objects are displayed or whether the F-Curves for all visible objects are displayed. The ghost next to it allows you to display the F-Curve of objects that are not displayed.