Actually, to my knowledge, we don't really have a category that shows all posts from all categories... maybe /recent, but we'll have to take a look at your site to see what you're talking about!
You can't get the current user data without their uid. If you have access to the express req object you can grab it with req.uid or if it is a socket call then its socket.uid. The value of uid is 0 if the user is not logged in.