Is there a way to get back system keys grabed by the OS?

Operating system grabs the printscreen-down and on linux running gnome all the alt-mouse combos grabbed by the OS. Is there a way to prevent this?

I doubt there’s any way to prevent it at the application level, but I bet there’s a way to configure gnome not to do that.


Some games disable alt-f4, windows key, etc.
Maybe it’s done by unregistering them, and restoring them at exit, the opposite of some apps registering some global hotkeys and clearing them at exit.

This is a good start for windows :