US woman forced to provide her fingerprint to unlock seized iPhone | Ars Technica UK. I know. You aren't a criminal. You have nothing to hide. That doesn't mean that you want an overzealous police officer or prosecutor to meander through your life on your smartphone. The law professors interviewed for this story recommend passcodes instead of fingerprints as security measures for smartphones. Fingerprints are considered physical characteristics, like blood type, and can be compelled. Passcodes can be argued to be testimonial, and not able to be compelled under the Fifth Amendment's right not to testify against oneself. Additional security measures, like encryption, that also requires a code or password for entry, also enhance security. Of course, it is impossible to perfectly balance the right to be secure in your person or papers as provided in the Constitution, with the right of the State to be secure from wrongdoers. The Courts create the balance. Citizens merely make judgments about what security measures they want to take. You decide.