Now they want to force you to unlock your phone. [Don't ever do this! – ed.]

The amount of personal data we keep on our smartphones is almost immeasurable, a reality the Supreme Court recognized in 2014 when it ruled that police must comply with the Fourth Amendment warrant requirement to search your device. But your phone has a simpler safeguard: a password that, under the Fifth Amendment, you shouldn't have to reveal unless the government overcomes your right against self-incrimination.

It's a right with deep roots, dating back to fourth-century Christian thinker St. John Chrysostom, who argued that no one should be required to confess their sins in public because it would discourage people from confessing at all.

By the 17th century, English common law had begun to develop these ideas into a right not to be interrogated under oath. The right achieved major recognition after the infamous Star Chamber sentenced prominent natural rights thinker John Lilburne to approximately 500 lashes for refusing to testify against himself. Lilburne remained a significant English philosopher and politician for decades while the Star Chamber was abolished just four years later.

Lilburne's case was so influential that colonial America enshrined the privilege against self-incrimination in nine state constitutions before it even became part of the Bill of Rights. Today, police act as if smartphones and digital technology invalidate those protections. They don't.

It doesn't matter if you haven't broken the law or you think you have nothing to hide. What matters is whether police believe—rightly or wrongly—that you have done something illegal or that you have something to hide. Police are incentivized not to protect rights but to arrest people allegedly (or actually) breaking laws.

Without a warrant and specific proof of incriminating evidence, police should never be allowed past your phone's lock screen.

Unfortunately, your Fourth Amendment right against warrantless searches and seizures is insufficient to stop police from scouring the trove of personal data on your phone for information unrelated to their investigation. Police can seize your device before they get a warrant and if they have the passcode nothing stops them from performing an off-the-record search—even if they might be later prevented from introducing that information in court.