@ObscurePen
If you notice that a user or several of them have a lot of broken images in their old posts, you can tag those users and post about it in this thread I created for that purpose:
Tag a user to update their broken image links Some have fixed their images after being mentioned, others don't care or haven't noticed the tag.
regarding the "another hosting service", are you perhaps referring to vgy.me? Recently a forum member posted that the images he uploaded from that image hosting have become broken.
That was me. I used that image host in the past, and just like Imgur, it also doesn't work on the forum anymore. TryNinja explained how to add some more code to his automatic image uploading script to include the pictures from vgy.me as well. It works if those images are still available and the host didn't delete them from its servers.