I need to block the possibility for a single user to change the desktop background, or at least to make it possible only by inserting his password on OS X Lion / Mountain Lion.
I want to lock every possibility, from iPhoto to Safari…
One possible solution would be to set the permissions on
~/Library/Preferences/com.apple.desktop.plist to be read-only for the user.
Found a way to stop background changing.
/System/Library/Services/Set\ Desktop\ Picture.workflowChange the extension. This stops right clicking a photo to set desktop picture.