The detection action system will allow you to decide what to do with the visitor if they are found to be using a proxy. You can redirect the visitor to a custom URL, show the visitor a blank screen or show the visitor a simple message.
If a visitor is found using a proxy they will be shown a blank screen. This will leave the visitor thinking the website either does not exist or that they are blocked.
If a visitor is found using a proxy they will be shown a blank screen containing a message. The message can be anything you like and should be as simple as "Sorry but we do not allow the use of proxy servers".