expressly allow calls from webpages originating from insertion data server 116 for example request monitor 202 can identify http requests originating from the inserted remote webpages and response monitor 204 can then modify the http headers of the http responses that are received in response to the identified http requests in order to identify http requests originating from the inserted remote webpages request monitor 202 can examine http headers of all incoming http requests and identify for example all requests having a simple request method i e options head get or post whose header includes the field u201c origin u201d and whose u201c origin u201d field corresponds to insertion data server 116 after identifying a request originating from an inserted webpage request monitor 202 can for example instruct response monitor 204 to intercept the http response that would be received in response to that request when the http response is intercepted by response monitor 204 response monitor 204 can modify the http response such as to indicate to internet access application that xhr requests issued from webpages hosted on insertion data server 116 should be allowed this can be achieved for example by adding to the http response the following w3c cross origin resource sharing u201c cors u201d headers http request options head get post http http 1.