I'm looking for filter content in Joomla in an hybrid way I would like have articles visible in public view, but when an user log-in the same article should be filtered according to the user's categories choice. I try to describe more clearly:

• An user during chooses, during registration process his interests in a list of categories.
• When a no-logged user views the page all the articles of every categories will be displayed
• When the user login,the articles should be filtered according with user's choice in registration process. So should be visible only the articles in categories chosen by user

Actually i didn't find a way to do this...any idea about it?

I'm looking for a way to filter content in Joomla in an hybrid fashion. I would like have all articles visible in public view, but when a user logs-in, the same articles should be filtered according to the user's categories choice. 
Let me try to describe a bit more clearly:

• A user chooses during the registration process his interests in a list of categories.
• When a non-logged user views the page all the articles of every categories will be displayed.
• When the user logs-in, the articles should be filtered according with user's choices from the registration process. So there should be visible only the articles in those categories selected by the user.

Actually I can't find a way to do this... any ideas?