The ACL model in Active Directory (AD) is flexible and granular. However, there's one restriction that Windows 2000 AD ACLs can't enforce: limiting the number of objects created in a partition. You can, of course, restrict who can create objects in a container, but after you give a user the ability to create objects (e.g., by using the Create All Child Objects right), that user can create as many objects as he or she wants. A malicious user who has the rights to create objects in a domain could fill up a domain controller's (DC's) hard disk simply by creating a lot of objects.
AD Quotas
Windows Server 2003 has a new AD quotas feature that lets you monitor and limit the number of objects a security principal (user, group, or computer) can create in a partition. This feature is similar to the built-in quota that Win2K and later versions assign to authenticated users for creating computer objects except that the new Windows 2003 quotas apply to all object types. For example, the new computer account quota limits users to creating no more than 10 computer objects (i.e., accounts) in a domain. . . .

