No need for /s. That's a valid concern that gets mentioned often in discussions like this. If a biometric sensor can be tricked by a body part that is no longe

No need for /s. That's a valid concern that gets mentioned often in discussions like this. If a biometric sensor can be tricked by a body part that is no longer attached to the body, that's a serious issue. But AFAIK at least modern sensors try to verify if it's still alive and then there's also the biological effect that a body part quickly changes its properties if it is no longer supported by the body. The biggest danger in that is probably criminals who don't know that it is likely that a detached body parts stops functioning.