Lets put the horses back in the stable! Rated 4 out of 5 stars
The bad ratings have missed the point. NO add-on can block everything since ALL of them are easily disabled!
On my site I give detailed advice on how to stay secure and private and much of it has ZERO to do with tech at all. In many cases that means not letting meth-head family members into the house. It means not hiring untrustworthy people. Sometimes that means living or working alone. Some people even put their computers in a safe when they are away! This is why secure locations have expensive and elaborate security layers. Expecting a simple add-on to give the same results is ludicrous.
When it comes to tech that means putting strong passwords on your computer itself and changing permissions on the administrator level. THOSE are the kinds of things that are going to keep those sites blocked.
The true use for this is a situational blocker for personal use-in other words just use it to make sure annoying sites never get allowed back on your screen. However When add-ons such as NoScript, Request Policy or even Killjasmin are used that also will keep unwanted surprises off of your screen.
Do not expect any add-on or program to defeat any human with physical access to your computer! The next issue is if people choose their sites wisely they really will rarely need to block anything.
The bottom line is it really is wrong for users to blame this add-on for their own high and low tech mistakes.