I'd like a plugin that display links to registered users only, is there any plugins that allows this?
From the point of view of a guest, he would see something like [Link available to registered users only] instead of the links.
Actually, it would be even nicer to be able to filter all types of content and replace it with another one related to the group of the user.
I know that it's possible
You'd want to create a plugin that acts on the filter:parse.post hook, and removes private information (of your choosing) based on whether the user is an admin or not.
but haven't find any plugins actually doing it yet