Hopefully they come back here and read this - and then can remember how they gained access in the first place, so it can change. It really is best if actual Last.fm users can generate this content, as staff actually involved in artist production have several different priorities and websites that they need to attend to, whereas Last.fm users themselves are always here, always using the service and can update pages whenever it needs to be done.
You can blame the Feeder staff themselves for that one - see the uploader ID? It links directly back to the main Feeder page, not an individual user. So around about the time this picture was current (Silent Cry), Feederweb got the right to add this (and the other picture that just won't go away) as an official artist, meaning that now only they can change it - Last.fm users image voting rights mean nothing in this case. However, they've obviously forgotten all about it, and when the Renegades campaign came around, (and now Generation Freakshow) they forgot about the process of adding official artist images when they came back to Last.fm, and instead tried to add new pictures with the standard user method. Check these new photos - the uploader links back to a 'Feederweb' user, but that's just a normal user profile they created, it doesn't have any sort of admin rights over their own artist.
So to sum up, they've foiled themselves by forgetting their old login details.