[ppa-experiment] what happens on opt-out?

[bernardpaulus]

Hello,

Could you describe in more details what happens if we opt-out, and what methods could the site use to know that we opted out?

More precisely, what are the return values of

navigator.privateAttribution.saveImpression(...)

and

navigator.privateAttribution.measureConversion(...)

when opted out versus the default (enabled)? Is there any exception thrown?

Also, how are opted-out users protected against being detected?

[martinthomson]

The API appears to function fully when someone is opted out, but no private information is released. That is, saveImpression appears to save something (but saves nothing), and measureConversion generates a measurement message that contains all zero values. From the perspective of the sites involved, things appear to be exactly the same as someone who has the feature enabled.

Our explainer should really cover this, but it doesn't, so I'll use this issue to track the addition of the above explanation to the explainer.

[OdinVex]

The API appears to function fully when someone is opted out

Where is an option to disable this API plagueware to begin with?

[rugk]

Where is an option to disable this API plagueware to begin with?

This obviously would make you trackable as you are 1 of 1mio or so users where the API, say, returns an exception or does not exist (while e.g. in the browser version it should exist) etc. So not a good idea…

The "noop" approach is indeed a good one when disabled.