Apple has announced that it is to introduce a new tool to its Safari browser, which will block third-party ad trackers. The feature will appear in the next versions of Safari, which are currently in beta. Apple has said that the new feature is all about protecting privacy. The feature will use machine-learning to identify tracking behaviour regardless of how the cookies are served, deleting any cookies after 24 hours. This means that popular sites such as web giants Google and Facebook, whose users are likely to revisit the same site within that time period, will be unaffected. However, third-party companies such as Criteo and Adroll, which coordinate cookies in the background of multiple smaller sites, are expected to be hugely impacted. These smaller companies will suddenly find it difficult, if not impossible, to target internet users with tailored ads based on their browsing habits.