With the convenience and security of biometrics comes a concern for privacy. For any biometric authentication solution to work, it requires a database containing the relevant information for each individual to be identified and authorized by the system. This means that every user's biometric signature would have to be recorded so that the solution could use the information to verify each person's identity. The safekeeping, ethical use, and governance of this information becomes critical.

In addition to the aforementioned, by their nature, biometric systems also collect more information than just the users' fingerprints, retinal patterns, or other biometric data. At a basic level, most systems will record the time and place a person is at the time of an authentication. This also leads to the concern over how and where this information could potentially be used.

Some final words on this particular topic: a recent court ruling emphasized the importance of providing (prior) notice of biometric data collection and use. Be careful when dealing with biometrics: violating the law will most likely result in you or your company being sued.