Do you use a password to lock your phone? Or do you use a fingerprint to unlock your phone through Touch ID technology? Many people think that a fingerprint would be more secure; however, it depends on who you are trying to prevent from getting into your phone. Thieves may find it harder to access your phone with a fingerprint reader. But when it comes to police investigators who want to look at the contents of your phone, a simple password may give you more privacy.

Case law has found that police cannot force you to enter your password or passcode on your phone to give them access to your text messages, call history, or files you have on your phone. Phone passwords are protected by the Fifth Amendment of the Constitution, which protects individuals from being “compelled in a criminal case to be a witness against himself.”

However, fingerprints may not be given the same protection as a four-digit passcode. The question before the court in Virginia v. Baust was “whether the production of one's passcode or fingerprint is testimonial communication and therefore subject to the defendant's Fifth Amendment privilege against self-incrimination.”

After a hearing, Virginia Beach Circuit Court Judge Steven C. Frucci found that a criminal defendant can be compelled to produce his fingerprint to access his smartphone, whereas he could not be compelled to produce his passcode. The difference lies in what is considered “testimonial” under the law. A passcode is in the mind of the defendant, and in order to give that information to police, he would have to divulge his mental process. This would be considered testimonial, which is protected by the Fifth Amendment.

On the other hand, a fingerprint was considered by the judge to be a physical characteristic, which was not testimonial. In order to access the phone, the defendant would not have to say anything, or communicate any knowledge, or “disclose the contents of his own mind.”

Other case law cited by the judge found that the Fifth Amendment does not protect against compelling a defendant to submit to fingerprinting, photography, or standing before a police line-up. Even though doing so may provide incriminating evidence, exhibiting physical characteristics is not treated the same way as communication or testimony of information inside the mind, and therefore is not protected by the Fifth Amendment.

Many have found the judge's decision troubling. Privacy advocates see the decision as a blow to privacy rights, especially after the Supreme Court ruled that the police do not have the right to search an individual's phone without a warrant. However, Hanni Fakhoury, a staff attorney with the Electronic Frontier Foundation, was not surprised by the ruling. “It's just a good wake-up call for people to realize that fingerprint ID doesn't necessarily provide the same sort of legal protection that a password does.”

The use of passwords to protect information from thieves and snoopers is becoming obsolete. However, as the use of biometrics, such as fingerprints, retinal scans, and voice recognition continues to rise, it may present a real risk to individual privacy.