Turn off the XDomainRequest object

This policy setting allows you to choose whether websites can request data across domains by using the XDomainRequest object. Note that this policy setting does not block client-side communication across domains through other features in Internet Explorer 8, and it does not prevent a site from requesting cross-domain data through a server. If you enable this policy setting, websites cannot request data across domains by using the XDomainRequest object. If you disable or do not configure this policy setting, websites can request data across domains by using the XDomainRequest object.