At the Children's Hospital.
My nephew was in the ICU on Thanksgiving, following surgery the day before. I was bringing his younger brother and sister to see him. As you approach the ICU, there are several large signs telling you that you can't use your cell phone, or asking you to turn your cell phone off in the ICU. To me, it doesn't matter *why* the hospital has this rule. The rule is there, it is most likely to help in the care of the children in the unit and you have the choice to follow the rule or leave. There are also several signs pointing out areas where cell phone use is allowed--two waiting rooms right outside the ICU, part of the hall, the rec room down the hall, the hospital lobby, etc. Cell reception in the hospital is pretty bad anyway, so the rule doesn't cause a lot of problems for people anyway.
There was a man who insisted on using his cell phone in the middle of the ICU main hallway. The staff at the desk asked him nicely to stop. A nurse told him to stop. A doctor yelled at him. The security guards ordered him to give up his phone. The police officers handcuffed him and led him away. What phone call could be that important? And more important than the kid he was there to visit?
On the other hand, the nice family next door to my nephew brought in a complete turkey dinner and offered to share with my SIL, who stayed in the room while my brother and the ambulatory kids all went to Uncle Ned's house for Thanksgiving dinner. SIL had two Thanksgiving dinners, because we sent my brother back with a plate of her favorites later in the day.