lock icon/button breaks a decade of established visual idiom
Submitted by Kortschak
Created attachment 215087 Real world example of use of lock idiom.
The lock icon in the User Accounts control used to lock and unlock the control is the converse of the established idiom.
That is the closed lock icon indicated an imperative verb to close the control (i.e. the control is not locked), where for the past decade or so in the GUI domain a closed lock icon (example the status bar in web browsers) has indicated the state noun that the control is locked.
The established idiom reflects the real world, where a closed lock indicates... a closed lock, and in other graphical representations of locking status for non-padlock type objects (for example the file attached).
Given that representation of verbs is difficult in graphic idioms without movement and particularly with small icons I would suggest that the the icon button set be changed from a closed lock in the button to indicate "lock the control" and an open lock in the button to indicate "unlock the control", to the more established graphic of a closed lock next to the button to indicate "locked" and an open lock next to the button to indicate "unlocked".