Indiana attorney William Webster says his client came to him with a quandary: Police wanted access to her smartphone and had obtained a search warrant. But officers couldn't get into the device without a passcode. The client, Carmel resident Katelin Seo, 37, was facing accusations of stalking and harassment. A Hamilton County judge ordered Seo to unlock the phone.

There was no specific case law that Webster could immediately cite, he told IndyStar, but something told him that being forced to hand over something so inherently personal was a violation. “At the time, it was hard for me to imagine that a defendant would be required to assist the prosecutor in the case,” he said.

After some discussion, Webster invoked Seo's Fifth Amendment right against self-incrimination.The Indiana Court of Appeals sided with Webster.

Next month, the Indiana Supreme Court will hear the case. Whatever the court decides could undermine either privacy interests and constitutional rights, or public safety and law enforcement, according to attorneys in the case.