Private content is available to Ektron administrators and users or membership users with at least Read-Only permissions for its folder. Those users must log in to work with private content. Unauthorized site visitors cannot see it. When you make a folder private, the content and any subfolders are also private (if they inherit permissions).
IMPORTANT: Private content is hidden from search results if your search provider is Microsoft Search Server 2010. It is not hidden if you are using another search provider.