I want the client I've created a website for, and to whom I have given limited powers as "Author" through the User Role Editor plugin to be able to upload media files to the media library, but NOT to be able to delete files already in there. The media library contains all the image files for the whole website!
I found this post from a year ago: http://wordpress.org/support/topic/how-to-disable-media-delete-in-wordpress?replies=2. It sounds like this solution is exactly what I'm looking for, but I don't know where to place this bit of code. Is it in functions.php or elsewhere?