„The Privacy Sandbox”

Google kickt Third-Party-Cookies und bildet Kohorten. Durch ihre Vormachtstellung bei Betriebssystemen (Android) und Browsern (Chrome) trackt Google damit deutlich besser als seine Mitbewerber.

Praktisch sieht das so aus: Android und Chrome schreiben alle von euch besuchten Webseiten auf. Über maschinelles Lernen sortiert man euch dann in eine Kohorte. Dieses Bündel aus Daten – diese Kohorten – benutzen nun Webseiten, um beispielsweise personalisiert Werbung auszuspielen.

Weil Google selbst diverse Services betreibt (YouTube, Google Suche, etc.), könnten sie über First-Party-Cookies (Anmeldedaten, etc.) präziser Interessensgruppen bilden.

Federated Learning of Cohorts” – kurz FLoC – nennt sich die Cookie-Nachfolge. Es ist eine Zusammenfassung all eurer Aktivitäten im Browser – über den Browser.

Und so beschrieb die EFF bereits vor eineinhalb Jahren ihre Nachteile:

This is, in a word, bad for privacy. A flock name would essentially be a behavioral credit score: a tattoo on your digital forehead that gives a succinct summary of who you are, what you like, where you go, what you buy, and with whom you associate. The flock names will likely be inscrutable to users, but could reveal incredibly sensitive information to third parties. Trackers will be able to use that information however they want, including to augment their own behind-the-scenes profiles of users.

Google says that the browser can choose to leave “sensitive” data from browsing history out of the learning process. But, as the company itself acknowledges, different data is sensitive to different people; a one-size-fits-all approach to privacy will leave many users at risk. Additionally, many sites currently choose to respect their users’ privacy by refraining from working with third-party trackers. FLoC would rob these websites of such a choice.

Furthermore, flock names will be more meaningful to those who are already capable of observing activity around the web. Companies with access to large tracking networks will be able to draw their own conclusions about the ways that users from a certain flock tend to behave. Discriminatory advertisers will be able to identify and filter out flocks which represent vulnerable populations. Predatory lenders will learn which flocks are most prone to financial hardship.

FLoC is the opposite of privacy-preserving technology. Today, trackers follow you around the web, skulking in the digital shadows in order to guess at what kind of person you might be. In Google’s future, they will sit back, relax, and let your browser do the work for them.

Don’t Play in Google’s Privacy Sandbox

Im ersten Schritt sollte Google keinen Applaus für diese „Building a more private web”-Initiative bekommen.

In a world with FLoC, it may be more difficult to target users directly based on age, gender, or income. But it won’t be impossible. Trackers with access to auxiliary information about users will be able to learn what FLoC groupings “mean”—what kinds of people they contain—through observation and experiment. Those who are determined to do so will still be able to discriminate. Moreover, this kind of behavior will be harder for platforms to police than it already is. Advertisers with bad intentions will have plausible deniability—after all, they aren’t directly targeting protected categories, they’re just reaching people based on behavior. And the whole system will be more opaque to users and regulators.

Google’s FLoC Is a Terrible Idea

Im zweiten Schritt ist entscheidend für welchen Webbrowser und für welches Betriebssystem ihr euch entscheidet.