Prevent folders and files in root


is there a way to prevent users to create files or folders in the home directory?

We use NC to exchange information but some users still dont get it that files that arent uploaded to a shared folder must be shared manually which is really frustrating to communicate. So instead I want to restrict users from doing exactly that. Users dont have private files in this cloud anyway and each user is member of a group.

The structure looks like this

-General (all have access)
-Group A (limited to A)
-Group B (limited to B)
-Group C (limited to C)