With cPanel 11.32 and above, you may prevent certain domain to be created from your server such as google.com, yahoo.com, microsoft.com, and etc.
To see which domain are blocked by default, view the file /usr/local/cpanel/etc/commondomains.
To block the domain to be created.
1. Create file /var/cpanel/commondomains.
2. Insert the domain list to the above file and each domain should be in new line.