Everyone knows it’s possible to go the fruit and vegetable section of the supermarket and inject an apple with poison. But no one does because the world has to operate with a certain amount of trust and, after all, everyone eats.

This is not a principle of civilization that is adhered to by a certain class of comedians and radio hosts to whom the prank telephone call has become a staple of their routine. They poison the apples every day.

Earlier this week a male-female radio team in Australia called the hospital where Kate Middleton, the pregnant Duchess of Cambridge, was being treated for severe morning sickness. They were pretending to be the Queen and Prince Charles, asking after Kate’s condition. A nurse named Jacintha Saldanha picked up the phone because no one was sitting at the duty station at the moment. She passed the call to another nurse who fell for the ruse and discussed the Duchess’s medical condition, a conversation that went out live on the radio in Sydney.

The DJs, Mel Greig and Michael Christian of radio station 2DayFM in Sydney, later said it was one of the easiest prank calls they ever made and they were surprised that the hospital didn’t hang up after hearing their terrible accents. They apologized and issued a canned statement saying, “We’re very sorry if we’ve caused any issues and we’re glad to hear that Kate is doing well.”

Kate maybe, but not the nurse. The Palace said the Royals did not complain to the hospital and no one was fired or suspended. But by some accounts, Mrs. Saldanha, who is married and has two children, felt terrible about it. And now she is dead, a possible suicide.

We all answer the phone every day with a certain amount of trust that the people who call are who they say they are. Stockbrokers, plumbers, lawyers, pizza restaurants, doctors, nurses and the Chinese takeout restaurant all trust the voices that call to do business.

Two nurses charged with care of the currently most beloved member of the royal family simply answered the phone and believed what they were told. They were unlikely to be sophisticated about the ways of radio DJ humor and certainly would not have expected to be on the radar in Sydney. The DJs should have known that at the least the nurses could have been fired for talking and it was only by the grace of the hospital and the royal family that they were not.

But the two nurses were held up to international ridicule and embarrassment just so two DJs and their audience of Aussies could have a few laughs. Who among us could standup to that?

A lot of DJs make their living like drunk teenagers alone on a Saturday night with a telephone. Radio DJs have called wives pretending to be a boss firing their husband for having sex in the office. They have pretended to be detectives at a murder scene, and they have called the unwitting proprietors of pizza shops. The two knuckleheads Opie & Anthony on April Fools Day one year said the mayor of Boston had been killed in a car accident, and the mayor’s daughter called in, believing it was true.

Occasionally DJs get fired, as Opie & Anthony were in that case, but not often enough.

What makes prank humor not very clever, and not funny, is that one of the easiest things in the world is to take advantage of another person’s trust. That’s why Sacha Baron Cohen, who is very smart, is not funny. His basic humor is to laugh at people who make the mistaking of trusting another person. Him.

Now a woman who is described as a dedicated nurse is dead, possibly only because she answered the phone and trusted that the people on the line were who they said they were.

The Sydney radio station has issued another statement saying that its DJs are shocked at the nurse’s death and that they have taken themselves off the air indefinitely. Fine, but where was their sense of decency when they dialed the phone? I’m not sure what more should be done with the DJs. Maybe we should poison their apples and see if they think it’s funny.