Can police officers examine a person’s cell phone if they don’t have a search warrant? That’s the question on which the U.S. Supreme Court is set to make a decision sometime this month.

Some Illinois police departments are already asking for warrants if they feel a need to search a phone for evidence of a crime, says Sgt. Mark Folkenroth of the Quincy Police.

“It’s still kind of up in the air. It’s really a gray area in law enforcement, so if we get a search warrant, we’re pretty much guaranteed that what we’re doing is legitimate,” he said.

He says he always gets a warrant before searching someone’s phone, to ensure that any evidence found will be admissible in court.

Privacy advocates believe that cops searching phones without a warrant is an invasion of privacy, because the phones contain or have access to banking records, e-mails, videos and pictures.

The Supreme Court justices are expected to decide the issue by the end of this month. The cases are United States vs. Wurie and Riley vs. California.