Now you can easily create unique feed URLs for each registered user in your WordPress site simply by adding Feed Keys to the end of the existing feed URL. Unique Feed Keys are made by hashing username or email against a randomly generated key. You can choose the key length and algorithm to use to hash the salt and the key together using new WordPress plugin called Private Feed Key. It adds adds a 32bit (or 40bit) key for your website users and creates a unique feed URL.
Role Scoper, a free WordPress plugin allows you to gain more control over reading and editing permissions in your WordPress site. Using this plugin you can assign restrictions and roles to your specific WordPress pages, posts and categories.
It is possible to show-hide categories based on your WordPress site user roles. The CaPa Protect is a free WordPress plugin lets allows you to hide or display categories based on user roles types like Editor, Author, Contributor etc. The plugin also provides you the feature of showing a message whenever a someone arrives without permission on a protected blog post of your website. Also you can simply hide everything and your user will not be able to know the existence of hidden post.
There are many different plugins in WordPress Plugin Repository that allows you to limit your website access in different ways. Now this tutorial explains you limiting your WordPress site access for logged in or allowed by IP addresses.
Restrict certain posts or pages for logged in users of your WordPress site using a simple admin interface. You can very easily hide few, all or none of your website pages or posts.