BoingBoing – Ellsworth Toohey: “Yesterday I wrote about Privacy Guide’s mobile phone privacy and security guide for protesters. Today, Randy Zar, CEO of Faraday pouch manufacturer SLNT wrote:

“Just want to let you know your cell phone is tracking you regardless if you have it in airplane mode or not.  It even ping’s when it’s turned off. There is only one way to know for sure that you are not being tracked. That’s to keep all signals from coming out or going into your devices.”

He’s correct. As reported in a 2013 Washington Post article, the NSA has been able to track turned-off phones since at least 2004:

By September 2004, a new NSA technique enabled the agency to find cellphones even when they were turned off. JSOC troops called this “The Find,” and it gave them thousands of new targets, including members of a burgeoning al-Qaeda-sponsored insurgency in Iraq, according to members of the unit.

So if you are serious about not wanting to be tracked, you need to block your phone from sending and receiving signals. A Faraday phone pouch is one way to do that. It’s made of conductive materials like metal mesh or metalized fabric that create an electromagnetic shield around devices. When electromagnetic waves hit the pouch, they create a current that generates an opposing field, effectively blocking all wireless signals like cellular, Wi-Fi, Bluetooth, and GPS from reaching or leaving the enclosed device. Of course, as soon as you remove the phone from pouch, it’s vulnerable to tracking again.”