Google allows advertisers to fingerprint you for even better tracking

They tried to keep it from prying eyes, but several people did notice it: Google made a pretty significant policy change regarding the use of fingerprinting by advertisers. While Google did not allow advertisers to use digital fingerprinting, the company has now changed its mind on this one.

Previously, Google did not allow advertisers to pass any information to it that

Google could use or recognize as personally-identifiable information.

permanently identifies a particular device (such as a mobile phone’s unique device identifier if such an identifier cannot be reset).

The second rule has been removed in the new policy. In other words, advertisers may identify users based on the devices that they use and may pass the information to Google for tracking purposes.
↫ Martin Brinkmann at gHacks

Google really tried to hide this change. The main support article talking about the reasoning behind the change is intentionally obtuse and nebulous, and doesn’t even link to the actual policy changes being implemented – which are found in a separate document. Google doesn’t highlight its changes there, so you have to compare the two versions of the policy yourself.

Google claims this change has to be implemented because of “advances in privacy-enhancing technologies (PETs) such as on-device processing, trusted execution environments, and secure multi-party computation” and “the rise of new ad-supported devices and platforms”. What I think this word salad means is that users are regaining a modicum of privacy with some specific privacy-preserving features in certain operating systems and on certain devices, and that the use of dedicated, siloed streaming services is increasing, which is harder for Google and advertisers to track.

In other words, Google is relaxing its rules on fingerprinting because we’re all getting more conscious about privacy.

In any event, the advice remains the same: use ad-blockers, preferably at your network level. Install adblocking software and extensions, set up a Pi-Hole, or turn on any adblocking features in your router (my Ubiquiti router has it built-in, and it works like a charm). Remember: your device, your rules. If you don’t want to see ads, you don’t have to.