Cloud access to USB attached storage

On my PR4100 I have cloud access to USB storage switched OFF. However, when I login to and access the PR4100 I can see and access the USB attached files. This I do not want to happen as I keep a backup of all users, and public, files on the USB device. Am I misunderstanding something about the USB cloud access option in settings or do you think this might be a bug I should report?

USB Content Availability is turned OFF by default and prevents the My Cloud device from creating thumbnails of the USB content.

When attached, the USB drive is mounted as a Public Share which can be made Private with managed access like a normal Share.

Great. I hadn’t seen that they had Public switched on. I’ve now switched it off and all works as I hoped. Many thanks.