Why not ditch the phone like they do in the movies?

from here

While they're are products that reputedly do block signals from going to or from your phone, a tin foil phone case isn't it. Heck, even the original tin foil hats are thought to serve more as antennas.

What gets me is where did the idea even come from? That's certainly not a technique known to popular media - in the movies and on TV they just throw the phone away.