If you have this installed in Firefox you might want to think about it.

Mozilla has banned the popular (250,000+ installs) YouTube Unblock add-on that allowed users to view YouTube clips blocked in their country.

 The reason for this move is because the add-on was caught disabling a Firefox security setting (code signing) which the allowed it to silent-install another add-on, which Avast (antivirus software) was detecting as malware. 

Earlier in 2015, the same plugin was again caught cheating when it was using an self-contained update system that was bypassing Mozilla's add-on review process.

  Users that want to get rid of the add-on can follow these steps provided by Ghacks.