The CAD Manager Control has been around for a few AutoCAD releases now but perhaps you may not have noticed this in the AutoCAD installation interface. It allows you to change some options of how AutoCAD is set on the local machine or in a network deployment.
You can disable the web access features of AutoCAD such as Communication Center, DesignCenter Online, and Subscription account access in the CAD Mgr Control or from your CD.
You install the CAD Manager Control utility from the Network Deployment tab of the CD Browser or run from the CD at \support\CADManagerControl\ You can even export a .reg registry file to push out using a group policy or other method to existing users in your network.
Cheers,
Shaan