Expand 'Policy Elements' Right-click 'Destination Sets' | 'New' | 'Set' Add the sites you wish to block. Finish the wizard.
Expand 'Access Policy' Right-click 'Site and Content Rules' Select 'New' | 'Rule' Rule wizard starts. Type in name of the rule. Next. Select 'Deny' | can check 'Iff HTTP Request...' for custom error page. Next. Select 'Deny Access Based on Destination' Select 'Specified Destination Set' Select the name of the destination set you created. Finish the wizard.