Problems encountered in trying to make the server behave exactly as required after compilation and installation are complete and the server is running.
The above fragment will control anonymous users however if a local user with a full account with up and download capability is abusing their space then the technical measures which can be taken are limited. Applying a sane system quota is a good start, using the mod_quotatab and mod_ratio modules may control the rates of upload/download making it less useful as a warez repository. In the end it comes down to system monitoring and good site AUP's and enforcement.