Also, even if they work as desired, if they're ever compromised [1], you're permanently unable to use that form of authentication, or permanently vulnerable to

Also, even if they work as desired, if they're ever compromised [1], you're permanently unable to use that form of authentication, or permanently vulnerable to services that use and/or require it. [1] https://en.wikipedia.org/wiki/Biometrics#Data_security https://en.wikipedia.org/wiki/Biometrics#Data_security