The drop box is write only, unless you specific otherwise. Actually, Apple's lay term for any folder or drive that is write only is "drop box." (Side note: Apple once included a schematic for a WOM, Write Only Memory, chip in it's Apple ][ manual. My father never got why that was funny). If you Get Info on a folder, drive, etc, you can change it's status under Ownership & Permissions.
For instance, if your a teacher you might want students to save documents in a common place, but not be able to retrieve them.
I micromanage shared network folders. I have only one shared network folder. In it there is a folder for back and forth sharing, a drop box, and folders for uploads and downloads.