WebKit Tracking Prevention Policy

Major new policy from WebKit, with inspiration credit given to Mozilla:

We treat circumvention of shipping anti-tracking measures with the same seriousness as exploitation of security vulnerabilities.

If a party attempts to circumvent our tracking prevention methods, we may add additional restrictions without prior notice. These restrictions may apply universally; to algorithmically classified targets; or to specific parties engaging in circumvention.

No Exceptions

We do not grant exceptions to our tracking prevention technologies to specific parties. Some parties might have valid uses for techniques that are also used for tracking. But WebKit often has no technical means to distinguish valid uses from tracking, and doesn’t know what the parties involved will do with the collected data, either now or in the future.

Unintended Impact

There are practices on the web that we do not intend to disrupt, but which may be inadvertently affected because they rely on techniques that can also be used for tracking. We consider this to be unintended impact.

Equating tracking with malware and security exploits is a major policy change, and absolutely correct. Notably, they are not respecting commercial interests at all. The user’s privacy comes first, and if there is commercial collateral damage from that, fuck it:

WebKit will do its best to prevent all covert tracking, and all cross-site tracking (even when it’s not covert). These goals apply to all types of tracking listed above, as well as tracking techniques currently unknown to us.

If a particular tracking technique cannot be completely prevented without undue user harm, WebKit will limit the capability of using the technique. For example, limiting the time window for tracking or reducing the available bits of entropy — unique data points that may be used to identify a user or a user’s behavior.

Hopefully, this will help close the email tracking-pixel loophole as well.

The ball is now in Chrome’s court to follow suit. I think Google could aggressively close these same privacy-invasive loopholes without losing their ability to serve targeted ads — they’d simply be limited to serving targeted ads to users who sign into Chrome with their Google accounts.

★ Wednesday, 21 August 2019