Today the Supreme Courtis hearing two cases on law enforcements ability to search a persons cellphone without a warrant. It is an important decision in a time where a hand-size device can contain troves of personal data, some of which may or may not be pertinent to a case.

The decisions boil down to the Fourth Amendment: What are unreasonable searches and seizures?

The decision could affect a wide swath of the population. The New York Times notes that 12 million people are arrested every year, often for minor offenses, and that about 90 percent of Americans have cellphones.

Currently, the courts allow law enforcement to do warrantless searches when a person is arrested. For example, if someone is pulled over and a cop has probable cause he might check the car. This is often justified as a way to ensure police safety and avoid the destruction of evidence.

In its entirety the Fourth Amendment reads:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

But what about a cellphone? Can a cop flip through your contacts, or browser history or Dropbox without a warrant? Are those papers or effects, or not?

The two cases being heard are on opposite ends of the spectrum. The first is Riley v. California. In 2009, David L. Riley had an expired car registration, and was pulled over in San Diego. Police also found two loaded guns and text messages that associated him with a gang. A further search of the phone linked him to an attempted murder. He was convicted and received 15 years in prison.

Both the guns and phone were found without a warrant; a California appeals court ruled that the search was like going through a persons wallet or address book and did not require one.

The second case isUnited States v. Wurie.Brima Wurie was arrested in Boston in 2007 on drug and gun charges. Officers searched his flip-phones call log without a warrant. A Boston federal appeals court threw out the cellphone records as evidence. Judge Norman H. Stahl wrote, Today, many Americans store their most personal papers and effects in electronic format on a cellphone, carried on the person.

See the article here:

Fourth Amendment in the digital age: Supreme Court to decide if police can search cellphones without a warrant