This is a terrible idea. The last thing I want is for an advertising company that makes its living off personal data that they gather about me to be able to reliably link that data to my real identity.
I think that in general embedding legally-empowered digital IDs (in the form of certificates, not pictures of physical ID cards, mind you) in mobile phones is a good idea, but it ceases to be a good idea when your phone and your OS are made by an advertising company with clear incentives to gather data about you, and a solid history of doing so.
I think that in general embedding legally-empowered digital IDs (in the form of certificates, not pictures of physical ID cards, mind you) in mobile phones is a good idea, but it ceases to be a good idea when your phone and your OS are made by an advertising company with clear incentives to gather data about you, and a solid history of doing so.