One big problem that modal dialogs help with is time spent permission checking, which the presenter hints at with his file viewer trying to access X:\Office\HR

One big problem that modal dialogs help with is time spent permission checking, which the presenter hints at with his file viewer trying to access X:\Office\HR Management. Let's say you have a list of things you can view, but you can only delete some of them (following some business logic about permissions, say). Do you provide a delete button on each of the items on the list, then show an error message for the items for which the user cannot delete and tried to? Do you spend a long time rendering the page to check the permissions of every item?