You’ve probably heard the phrase, “I plead the 5th”, before. It references the 5th amendment of the United States Constitution, which protects citizens in a number of legal situations. The entire text is below, but the part that it’s relevant right now is the part that protects citizens from needing to testify against themselves. This has protected those with charges levied against them from being forced to input their password and unlock their phone. With the iPhone 5s, Apple introduced a fingerprint sensor to the iPhone, and other Android manufacturers have followed suit. A court ruling has decided that cellphone owners can be forced to forfeit their fingerprint to unlock their devices. If you lock your smartphone with your fingerprint, you could be forced to unlock it if you’re under scrutiny from the law.
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
-5th Amendment of the U.S. Constitution
The ruling was expected since Apple announced the fingerprint scanning feature for the iPhone 5s. Defendants in criminal cases are fingerprinted, they can be asked to submit their DNA, and they can also be asked for their keys or personal property to unlock their home, car, or safe. However, those defendants cannot be asked to give away their safe combination, as this is personal knowledge that can be used to incriminate the defendant, and therefore they cannot be forced to give it away. This is why phone passcodes are protected, but your fingerprint is not.
iPhone owners, there is some good news. If you turn off your phone when you get in trouble, your fingerprint won’t be enough to unlock it. When booting, an iOS device needs to have the passcode entered, regardless of whether or not the user has enabled Touch ID. This means that as long as you can turn off your device before forfeiting it to police, your information will be protected. It also means your personal photos and conversations will remain private.
One thing is certain, regardless of who you’re trying to keep out of your phone, every smartphone user should password protect their devices. If you want, you can also use your fingerprint for fast unlocking (especially since it actually works on iOS devices), but remember that the most secure option is to only use an alpha-numeric passcode.