Know your cellphone privacy rights

You don't have to be a mafia kingpin or a drug dealer to find yourself being searched or interrogated by police officers. Even something as routine as a highway checkpoint can lead to law enforcement taking an interest in your personal property.

Which leads to interesting questions where law and technology intersect. For example, can police search the contents of your smartphone?

Thanks to a landmark Supreme Court decision last Wednesday, we now have a definitive answer to that question: No, they can't. The court ruled unanimously that cellphones aren't the same as other personal property and shouldn't be treated as such because they contain far more personal data than a person could reasonably carry.

Chief Justice John Roberts wrote: "Most people cannot lug around every piece of mail they have received for the past several months, every picture they have taken, or every book or article they have read -- nor would they have any reason to attempt to do so." Moreover, cellphone searches tread into remotely located property because these devices now permit authorities to see content stored in the cloud, which isn't physically on the person at the time of the search.

All that said, you might still encounter enthusiastic law enforcement professionals who attempt to circumvent the court decision and search your phone anyway. Know what you should do.

First and foremost, this advice assumes you aren't guilty of, or are a suspect in, a very serious crime. If the police believe someone is at risk of imminent harm or there's an imminent thread of destruction of evidence, they can invoke exigent circumstances and seize your phone anyway.

But for more mundane situations, your best course of action is to make sure that your phone is protected with a password or passcode so police can't simply take it and start reviewing its contents without your permission.

If you fail to lock your phone, or if police demand that you unlock it, you should calmly but clearly repeat to the officer (and nearby witnesses) that "I do not consent to this search." Repeating the phrase helps ensure that no ambiguity exists about whether you've consented to the search, according to Jay Stanley, a senior policy analyst for the American Civil Liberties Union. Stanley explains that such ambiguity can lead to a court fight over whether you consented to the search.

If the police persist, verbally indicate that you believe the search is unconstitutional under the Riley v. California decision, which is one of the cases that served as the foundation of the court's ruling.

Of course, stay polite and professional, and under no circumstances allow yourself to escalate the situation to a physical altercation. You'll lose, both physically and legally.