Rated 5 out of 5 stars
Works and does it job.
A small tip for those who want to block "service X". Use the system's "hosts" file for this and block the all known domains, it's guaranteed! :)
First review Rated 5 out of 5 stars
When this add-on is enable you can't visit "www.twitter.com"! If you select it in new tab, your page will be blank and that's all.