You are right. The users can only see the news that they have an assigned category for. That works like a charm. However, in the drop down menu of the admin panel they can still see all news items and delete news items. I would like my users to not be able to edit but only view what they are assigned to, so this list would be empty if that user is not assigned to that category.
I have done this in the albums via view unpublished items and that works amazing. "Managed news categories" in the group setting does not have the same option where you can untick the box edit, like it has in managed albums. Is there a trick for this? Or code I can tweak?