System Information
Windows 10 x64
NVIDIA GeForce w/ 1GB GDDR5

Blender Version
2.77a abf6f08

Short description of error
It's exactly as the title suggests, using fly-through mode while in camera view causes 3D objects parented to the same object the camera is parented to to move with the camera.

Exact steps for others to reproduce the error
You can repro this on a blender file with the default factory settings loaded.

1. Create an empty object (Shift + A -> Empty -> Plan Axes)
2. Duplicate the cube by selecting it and pressing Shift + D, Then move it around so both cubes are visible in the 3D view
3. In the outliner, select one of the cubes and the camera, then the empty object and while hovering over the 3D view press Ctrl + P -> Object (Keep Transform). It really does not matter which parenting option you choose, the result is still the same.
4. Go into Camera view by either pressing Numpad + 0 or on the 3D View click on View -> Camera.
5. Start Fly-through mode by pressing Shift + F, then start moving around. You should see the cube that is parented to the same object the camera is parented to is also moving with the view while the other cube is not. If you leave camera view and go back to user perspective view, then start fly-through mode again, that problem does not happen.