Call It the ‘MacGyver’ Fix: Aluminum Foil May Solve Cell Phone Search Dilemma.

A group of criminal law professors have come up with an easy solution for balancing the need to protect evidence stored on an arrestee's cell phone and the Fourth Amendment rights at issue in Riley v. California and United States v. Wurie—aluminum foil.

The same material that protects my son's peanut butter and jelly sandwich can also protect cell phones from being remotely "wiped" before a search warrant can be obtained, the professors argue in a March 7 amicus brief to the U.S. Supreme Court.

The shiny wrap can act as a cheap stand in for what is known as a "Faraday envelope"—aka "Faraday bag" or "Faraday cage"—that can block electronic transmissions to and from a cell phone, the professors explain.

But even true Faraday bags—currently used by law enforcement agencies across the country—won't break the bank. The brief notes that the top of the line envelope, complete with a clear window to manipulate and examine the contents, is sold for $58, with basic versions costing only $6.95 each.

But if police departments can't cough up $6.95, "they can have officers create their own Faraday envelopes for mere pennies by using aluminum foil sold in grocery stores," the professors tell SCOTUS.

This example of metallurgic ingenuity is part of the professors' larger point that the government's interest in protecting information stored on a cell phone can be met without searching the device at the time of an arrest.

"Rather than allowing warrantless searches of cell phones incident to arrest, the Court should encourage law enforcement officers to place cell phones in Faraday envelopes or aluminum foil to prevent the remote wiping of data from the phone while officers seek a warrant," the brief says.

After all, why allow officers to peak into a treasure trove of data that could contain a "warehouse full of documents, pictures, and GPS data," when protecting that information requires just a trip to the pantry.