Share without account vs share with

[SxM]

Someone know why :

If i share my usb disk without account i can browse the root folder of my disk, where all my files are stored

If i share with account i can browse only the subfolder

Am I doing something wrong ?

2)Anyone one from wan can explore my disk ? How can i protect it ?


Ps:I would like to set an account to block write mode on the root disk (where my files are stored) to prevent my children to delete some files