Disable or remove permissions for Scald page display
This is a partial answer, simply blocks non-logged in visitors:

function MYMODULE_init() {
  // Prevent public users from seeing the atom pages
  global $user;
  if(arg(0) == 'atom' &amp;&amp; !$user-&gt;uid) {
    drupal_not_found();
    exit;
  }
}


I would really like it if there was a permission on the scald module, logged an issue on d.o for that https://www.drupal.org/node/2512692.

Edit: there is a patch on that d.o issue which adds a permission to 'access atom page view', which is a better solution to the use of  hook_init() above.