"they block tracking" They block some tracking. What percentage of tracking they block is anyones guess. 99.999%, 90%, 50%, 10% ? Who knows. Also, they don't

"they block tracking" They block some tracking. What percentage of tracking they block is anyones guess. 99.999%, 90%, 50%, 10% ? Who knows. Also, they don't block targetted tracking, which would be used by a stalker for example. They only block widespread well known trackers. Only way to be safe is to disable loading of all remote resources and don't click links.