check for link rot
'Link rot' is a term for when pages go away and links no longer resolve. On the detail and list views of links, do a quick check to see if the link still goes through. If not, show a little error icon and message.
Use ajax to asynchronously verify that the pages linked to don't return 404, 403, or 500. https://stackoverflow.com/questions/2955947/how-do-i-get-the-http-status-code-with-jquery