The Public folder is set with FTP service running. Within the Folder Share Permissions page, it’s Public Access is NOT enabled. Within same page, it’s access is granted for no group/no user.
Any file is then accessible with anonymous FTP browser syntax.
Example: let say you put a file test.txt in your Public folder, then anyone on earth can access it by entering this line into it’s browser:
Pay ATTENTION, your private data are just publicly available with WDSharespace running FTP server service.
Edit: firmware version 2.02.93