The user has private files.
1. Edit your private files, launch file picker, pick a file from (file system)/(box.net)/(dropbox)/(server files) repo plugin respectively, and check "Create an alias/shortcut to the file"
2. Click added file in file tree, make sure it is viewable
3. Create file or folder resource, pick this file from private area as reference, save it, make sure this file is viewable in module
4. Create file or folder resource, pick the same file from private area as a copy, save it, make sure this file is viewable in module
5. Update the file in the external repository and confirm that the file is also updated in #3 but is not updated in #4