I have this same problem with my DL4100. The MyCloud\Nobody account creates a folder called USB_Import in the Public share whenever you run a USB to NAS backup job. Your normal account can view the contents but cannot modify or delete them. The permissions on the created folder do not inherit from the parent Public share and do not match the rest of the folders in Public. Programming / coding / firmware error perhaps? If anybody has a non-SSH solution or can confirm if they have the same issue when using the same method that would be great.