[Samba] Samba server running in AD domain, local users can still access share

[David Roid]

Hello all,

I have a Samba 3.5 server running in an AD domain and domain users can
access nonpublic shares with their credentials. Good since this is what I
want.

However accidentally I found that local users (of the server itself) could
also access nonpublic shares with their credentials. Is this a bug or Samba
works this way, accepting both local and domain users? Is there anyway I can
make the server just dedicates to AD domain users?

Thanks and Regards
David