Err. Googleusercontent is owned by Google. It's used to host user content so that it's not under the Google domain and avoid XSS vulnerability.
It also seems like he kind of rushed off to post the article without a response from Google "This issue was disclosed to Google, but seeing as it is in public search results I thought it best to publish this to make others aware of the issue. "
Kind of ironic that the about page claims he runs "a software engineering consultancy providing leading edge software and security expertise"