There are many different reasons why webmasters want to block users from using incognito browsing.
For example, some users use incognito browsing to bypass content payments. In addition, the current functions incognito (private browsing) in most browsers also ship with anti-tracking features that prevent websites from tracking and monetizing your traffic.
Both of the above issues that appear with the use of private browsing result in immediate financial losses on the websites.
In early 2019, Google decided to stop these scripts. THE Chrome 76, released in July 2019, included an update that prevented websites from using the FileSystem API to detect when a user is using Chrome's normal browsing mode or anonymous browsing mode.
Before Chrome version 76, the FileSystem API simply wasn't there available στην κατάσταση ανώνυμης περιήγησης και οι διαχειριστές των ιστοσελίδων μπορούσαν να στείλουν απλά ένα query σε αυτό το API για να μάθουν αν κάποιος χρήστης χρησιμοποιούσε την κατάσταση ανώνυμης περιήγησης ή όχι. Με το Chrome 76, η Google ενεργοποίησε το API FileSystem για την λειτουργία ανώνυμης περιήγησης καθιστώντας τα προηγούμενα scripts ανίχνευσης εντελώς άχρηστα. Ωστόσο, αυτή η ενημέρωση περιείχε Mistakes.
Google did not fully enable the FileSystem API, but set a limit on the size of storage space that anonymous browsers could access at 120 MB.
It took developers less than a week after the release of Chrome 76 to find out what was going on and develop scripts that explored the FileSystem API to determine the amount of storage space a site could access. This way they could indirectly detect whether a user was using incognito mode or not.
Answering a question from Bleeping Computer, Google promised in August 2019 to fix the bypass and block anonymous browsing.
However, nine months later, it is still possible to detect anonymous browsing in Chrome and all other Chromium-based browsers, such as Edge, Opera, Vivaldi and Brave.
At the moment, we don't know of any date as to when a patch will be released that fixes the issue, but Google may be more interested than ever in fixing this issue.
On Tuesday, the company accused that it was secretly monitoring users, even in incognito mode.
Note that blocking incognito status detection will not prevent advertisers from tracking users, as both administrators and advertisers will still see information such as IP addresses and other traffic data. However, it will help Google win over some privacy-conscious users.