Safari is not open-source, so outsiders can’t look into any of its code to see what particular private data it collects. Apple assures us that Safari saves only the data necessary to “improve your future browsing experience”, such as your browsing history, you browsing cache, your download history and your login credentials.
Researchers from Google’s Information Security Engineering team recently found several security issues in Safari’s ITP anti-tracking system, claiming ITP actually leaks Safari users’ web-browsing habits, allowing persistent cross-site tracking, and enabling cross-site information leaks. Some of these issues have been addressed in later Apple security updates, but that is not quite enough to quell our suspicions of Safari’s privacy risks.
