I have issues setting file system (private) for users as described here. I wonder what they ment by
"This setting is used as the preferred download method. The use of public files is more efficient, but does not provide any access control."
If i want let only user that uploaded file have access to the file, which setting should i choose, and what are drawbacks?
Moreover, could if i choose private system, could i control access by module (for exaple User relationships module, so the friends of user could download the file)