Yeah, I also don't like it so much here. But let me explain:
The main things done here are turning relative image-/favicon-paths in absolute URLs and the deletion of the attachments of feeds/items.
* the deletion of attachments can actually be done in the business layer, so i agree here and I will move the functionality
* but the URLs have to be modified on every request of an item (resp. feed). If this is not done here, <i>every</i> business layer function that returns items (resp. feeds) must do this (e.g. call a modifyURLs-function). So I think it could be better to do it at a central point right after they get out of the database.?