If you set permission PRIVATE for an image and add subscriber groups, it should be only visible to those groups. This is only partially working. If you include said image via bbcode, you see the image right inside the article, despit it being private. The only thing that is being blocks is when you CLICK the image, then you do not get the full version but only the customized forbidden page instead.
Hey Tillerz that was always the case (no change there) - I cannot make a massive change like that without a massive update notice to everyone on the website because that might mean hundreds of thousands of images becoming suddently inaccessible to people. I am not against changing that but it will require a big announcement - this would be considered a feature change