After attending a CEH security seminar, you make a list of changes you would like...

After attending a CEH security seminar, you make a list of changes you would like to perform on your network to increase its security. One of the first things you change is to switch the RestrictAnonymous setting from 0 to 1 on your servers. This, as you were told, would prevent anonymous users from establishing a null session on the server. Using Userinfo tool mentioned at the seminar, you succeed in establishing a null session with one of the servers. Why is that?