is Firefox phoning home to Mozilla all the time like Chrome does with Google? I mean how else are they able to control the Click to Play feature and determine what's 'bad' for us to run.
contains a list of add-ons that Mozilla considers to be harmful to the user (contains security vulnerabilities, adversely affects browsing experience, etc.). Any installed add-on on the block list will be disabled and any attempt to install an add-on on the block list will result in an error.
(Additionally, there has to be more to it then just that, some interaction with C2P, in this case, but I'm not sure what.)