You can control access to the various Wildcat! Internet Hosting servers on a per access profile basis.  See wcCONFIG | Access Profiles | Internet options:

If you are upgrading,  the first time you run the Wildcat! Server again, it will automatically update all the access profiles to set the internet access options.  It will enable them so that your users are not locked out, thus making it work under your previous setup where there was no easy method to lock out users from specific internet servers. Now you have this ability, so check your access profiles if you want to limit control access.  For example, if you have Anonymous FTP, you should only give this access profile  to the FTP server.