Browsers provide sites with different APIs through which they can receive important metrics and then use them to compose a “portrait” of the user. For example, recently Idle Detection API appeared in Google Chrome – now web pages will know when you are using a PC (recently an article about this was published on the site). This is clearly not the kind of information that should fall into the wrong hands.
How does it work
There are four levels of protection to choose from, each with a different filtering severity. So, the zero mode disables all the functionality of the extension altogether. The other three are more complicated.
Includes minimal protection. According to the developer, this mode makes only those changes that will not “break” the sites. With it, the time values of events are rounded, the accuracy of geolocation is reduced to several hundred meters, the Battery Status API is disabled, which allows sites to receive information about the battery charge level.
Most balanced – does not break most sites, but disables many more vulnerable functions. For example, the time of events is rounded up even more, and the location accuracy is already several kilometers.
The third level of protection is useful only in some cases, the rest of the second will be enough.
Does the extension protect against surveillance?
Only partially. Disabling some APIs can reduce the number of vulnerabilities, reducing data accuracy increases privacy. However, the extension will not be able to completely protect against the creation of a unique “fingerprint”. There are other ways to obtain personal data from users. And blocking a set of specific APIs can only make it easier to get a browser fingerprint.