Biometrics are an essential part of a time based economy. It is our best means of preventing inflation of currency. In time based economy inflation occurs when a single person is able to commit their time more than once to the currency's value. This can occur in Prometheus if the network has non-unique members.
The biometrics information gathered to verify uniqueness of accounts will never be used for any other purpose. It will never be shared with any outside system and will be encrypted and protected to the same degree as any other form of personally identifiable information. Account information such as name within network may always be changed but your biometric information must remain unique and unchanged.