“The police generally may not, without a warrant, search digital information on a cell phone seized from an individual who has been arrested.”

The Supreme Court’s unanimous decision in Riley v. California Wednesday will provide people with a modest fig leaf of protection in today’s seemingly lawless police environment.

Police officers will still be able to search cell phones and other digital devices as long as they first obtain a search warrant from a judge. Obtaining a search warrant can happen swiftly in the digital age, but officers will need probable cause that a crime is being committed before searching through someone’s cell phone or tablet.

Groundless searches where an officer is just looking or “fishing” for something illegal in a person’s phone without probable cause has been affirmed as unconstitutional by the Supreme Court.

There is an exception to this newly defined case law, but officers will need a very good reason to use it.

“A warrantless search is reasonable only if it falls within a specific exception to the Fourth Amendment’s warrant requirement. The well-established exception at issue here applies when a warrantless search is conducted incident to a lawful arrest….although the search incident to arrest exception does not apply to cell phones, the continued availability of the exigent circumstances exception may give law enforcement a justification for a warrantless search in particular cases.”

In other words, during an arrest – not a detention – police will be able to look through a cell phone only in an emergency circumstance, such as where an officer believes there is an imminent bomb threat. We may as well call this the “one-in-a-million exception,” because that’s how often this exception is likely to be validly used.

The police have long been able to search people during an arrest to ensure that the arrestee does not have a weapon, and the court’s ruling also re-affirmed this procedure, meaning officers will be able to examine the outside of an arrestee’s phone. However, this does not mean that a police officer who detains someone can demand to inspect a person’s cell phone. The law only applies to someone who is being arrested. If you’re simply being detained, keep the camera recording.

Digital data stored on a cell phone cannot itself be used as a weapon to harm an arresting officer or to effectuate the arrestee’s escape. Law enforcement officers remain free to examine the physical aspects of a phone to ensure that it will not be used as a weapon—say, to determine whether there is a razor blade hidden between the phone and its case. Once an officer has secured a phone and eliminated any potential physical threats, however, data on the phone can endanger no one.

And remember, just because you have a right to record the police in public and police need a warrant to search your phone does not mean there are no officers willing to act outside the law. If you haven’t yet downloaded an app that protects your footage, check out FiVo and PicAway (tell us what you think as these are both relatively new).

For news tips on aerial photography and drones, contact Andrew Meyer, PINAC’s staff writer covering UAV photography, the First Amendment, and more. Follow him on twitter @theandrewmeyer.