Comment 21 for bug 344228

David Siegel,
There is also another problem with backing up the file, there are scripts which allow to randomly keep switching wallpapers , so this would lead to lot of unnecessary read-writes.

What Michael said makes sense , inotify watch for the active wallpaper is better...
For the use case when the image is in an external drive.
On trying to remove the drive, System should warn that the wallpaper image is on external drive and needs to be copied to hardisk.

This would be better.