Mercer model of prank calls: Let the person in on the joke before things spiral out of control.

CNN: DJs broke 'Do No Harm' rule

Disc jockey Michael Christian may be correct that prank calls are part and parcel of radio programs around the world.

CNN: DJs broke 'Do No Harm' rule

He has responded to the death of Jacintha Saldanha by suspending prank calls and withdrawing adverts for his Christmas compilation.

BBC: The end of prank calls?

These prank calls earned the nickname "swatting" because law enforcement agencies sometimes would send SWAT teams to respond to the false emergencies.

CNN: Ryan Seacrest's home 'swatted'

And the network, Southern Cross Austereo, suspended all prank calls, pulled advertising and ordered a comprehensive review of relevant policies and process.

CNN: STORY HIGHLIGHTS

Reports of marmalade theft and a chicken walking down a road are amongst "silly prank calls" received by Greater Manchester Police over Christmas.

BBC: Marmalade

The force's Diane Grandidge said Christmas and New Year were "the busiest times of the year for our team, which is why we would urge those making silly prank calls or thoughtless requests to think twice".

BBC: Marmalade

Prank phone calls and other practical jokes have long been a form of entertainment on radio and television.

CNN: Nurse death sparks outrage, casts glare on 'shock jocks'

He warned that prank 999 calls were a crime and said people had been prosecuted in the past.

BBC: Manchester United fan calls 999 over Nani's red card