Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
The :-moz-user-disabled
CSS pseudo-class is a Mozilla extension that matches elements representing images that were not loaded because images have been entirely disabled by the user's preferences.
Note: This selector is mainly intended to be used by theme developers.
Syntax
:-moz-user-disabled
Examples
Styling user-disabled elements
:-moz-user-disabled { background-color: lightgray; padding: 8px; }
Specifications
Not part of any standard.