With the current way the system works right now, image use for thumbnails is not tracked but videos added or pdf resources used in a course lesson are tracked appropriately. I have accidentaly deleted the wrong image only to find out later when I see blank images on my site. Come to find out that image use on course thumbnails and other locations are not being tracked appropriately as used (see image). Please fix. And if this can be done alert upon deletion if an asset is being used and force an overide to delete, or beter yet allow you to open a list of linked resources that will need to be reset if you want to replace.