acl msn dstdomain loginnet.passport.com
http_access deny msn
acl msnmessenger url_regex -i gateway.dll
acl MSN req_mime_type -i ^application/x-msn-messenger$
http_access deny msnmessenger
http_access deny MSN
acl webmsn dstdomain webmessenger.msn.com
http_access deny webmsn