Airplane mode defeats the point of a Faraday cage. Just put it in airplane mode before leaving your house. Also, is this really something privacy-focused people are ignorant about? I thought it was common knowledge by now.

What I'm wondering about, however, is whether or not wifi has the same effect. Will I get tracked if I keep it on? Snowden says you will, but he doesn't explain how it works. Why would my MAC address leave the routers that have me in range? I did notice that the public hotspots all use the same network, but it requires that the ISP has access to all those routers. Furthermore, isn't the MAC address spoofed on newer versions of Android? So this is something I'm not worried about, I keep wifi on even when I leave the house.