'Followers' widget for Google sites and blogs does not work with HTTPS Everywhere
If you enable HTTPS Everywhere, and surf to e.g. rainbowtux.blogspot.com (my blog), you do see an empty Followers widget at the left side. Without the plugin enabled, you see the Followers widget correctly. The rule responsible for this is the 'Google Services' one.
I tested this in Firefox 16.
Trac:
Username: evdvelde
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