In the UK chief constables can instruct the mobile phone companies to disable mobile coverage for Joe Public over all or part of their forces area.
This already happens. When GB II visited tyhe UK last year, there was a comms blackout around the motorcade. So your phone might be off the air for several minutes without any warning, apology or compensation.
Certainly this is all @rse covering stuff by the FBI and if they are on, it's over.
When the call comes would they simply abandon the trolley and their wife as they make a dive for the door.
Yes! Last year, I was in a crematorium and someone's mobile phone rang - right in the middle of the funeral ceremony. He just stood up and answered it, as he was walking back down the aisle to leave the hall. Obviously his friend meant a great deal to him.
--------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.