Blog 3 blog categories for 3 usergroups - how to prevent cross posting abilities?
 

Just for the sake of the argument, I've created 3 usergropus, let's call these 3 groups Father, Mother and Child. On the blog site I've created 3 blog categories, Fathers, Mothers and Children. In Fathers blogg I want only the Fathers to be able to start a blog, but where a Mother or a Child should be able to post if they so wish (granted the blog-starter has opened up for it). And vice versa: The idea is that each usergroup should have their own "sanctuary".

Any possibility?

Cheers!
Geir