Blocking ajax.googleapis.com
results in a red bar that says:
[This site] requires external JavaScript from another domain, which is blocked or failed to load. Retry using another source.
Once that link is clicked, the bar is gone, but you get redirected to the home page. If you go back one page in the browser's history, the bar is still there because of caching, so the page has to be explicitly reloaded.
Feature request
Clicking the link should return the user to the page he was viewing.