Reflecting on this, I wonder if a PaaS solution that is a "vault" of confidential information would be a good thing.
Similar to how Stripe handles payments with a token, we could all store tokens for User information (eg the Id) and query the vault (or operate on the vault, eg, validate login, or return email, etc) using keys.
The service could be hardened (like Stripe) to ensure the data is stored securely, and detect ex-filtration attempts (eg, queries for multiple customers at once being abnormal) and automatically block that.
Similar to how Stripe handles payments with a token, we could all store tokens for User information (eg the Id) and query the vault (or operate on the vault, eg, validate login, or return email, etc) using keys.
The service could be hardened (like Stripe) to ensure the data is stored securely, and detect ex-filtration attempts (eg, queries for multiple customers at once being abnormal) and automatically block that.