Well cell phones generally don't work in tunnels, and office buildings. These rooms are shielded specifically to prevent electronic easedropping from sophisticated devices so I would believe and ordinary cell phone would not circumvent such precautions.
However, it is true that nothing can be taken for granted after 8 years of Clintonian sabotage.
Perhaps in the U.S. this is true with the standard issue low watt phones and lousy cell infrastructer.
Would you like me to give you a ring from the tunnel under the Hong Kong harbor or from inside the elevator of my building? Signal at 5 bars.