Earlier quoted context omitted.
This is also not GDPR compliant, not that anyone actually bothers to enforce the law. If we respect the GDPR then data sharing for Facebook Login should only happen once the user presses the Facebook login button (as at that point the data sharing becomes essential to provide the functionality). As far as ad/marketing attribution it should be opt-in as that is not an essential requirement to provide the service (and…
Re: Ad/marketing attribution, that's not necessary correct. If the data point that gets sent back to Facebook is a GUID type string that matches the GUID that got generated when you first clicked the Facebook ad for the app and doesn't include data about you specifically, I believe that's fine. I don't myself have up-to-date information what data Facebook receives via its SDK but I suspect it is GPDR compliant throug…
Knowing Facebook, that GUID would surely be bound to the user, still leaking to Facebook that the user is now using the app.
An ad campaign ID (same for all ads of this format in this campaign) sent to the app developer (which can then aggregate them on their side and send the daily aggregated data to Facebook) would be better.