Here's the science lesson for dummies condensed into a paragraph:
If a Faraday Cage is in effect, 100% of the signal is blocked. It's an on/off deal. If you get a signal, the Faraday Cage doesn't work at that frequency. If you don't get a signal, it's working. Lightning will strike the outside of a car, plane or train and leave the passengers intact, yet the gaps (windows) in the metal frames allow really high frequencies in.
Come on, how on earth can GPS work on an iPhone in a car if you're sat in a Faraday Cage? Think about it.
If you're going to use science to explain something, at least have a basic understanding before you post something controversial and scary.
ps. The link that proposed the horror story, was it by any chance selling something? That should be a give-away to at least check google/wikipedia before telling us we're cooking ourselves.