title: Drupal 7: how to restrict file access to specific user roles
body: <p>I need to develop a site on Drupal 7. I have some content types with File fields in CCK. And access to nodes of these types should be granted only to specific Drupal user role. And at any moment site administrator should be able to make these Nodes 'public' or 'private'.</p>
  
  <p>I can make nodes visible only to specific user roles, but this is not secure enough. If anonymous user knows the path to file ( www.mysite.org/hidden_files/file1 ), he can download it.</p>
  
  <p>What is the most elegant way to solve this problem?</p>
  
  <p>Thanks in advance.</p>