Legality
Prank calls range from annoying hang-ups to false calls to emergency services or threats. Prank calls that waste the time of emergency services are a criminal offense in most countries and are considered telephone harassment in the US.
One such hoax call occurred in Perth, Australia, on New Year's Eve 2002, when a drunk teenager called the new anti-terrorist hot line to report a bomb threat against the New Year's Eve fireworks celebrations. The threat was taken seriously, and the celebrations were about to be cancelled when police discovered that no such threat existed. The teenager was then arrested for the false report.
Tension was also caused in December 2005, when a commercially operated radio station in Spain (COPE - owned by a series of institutions affiliated with the Catholic Church) played a prank on Bolivian president-elect Evo Morales. The hoaxer pretended to be Spanish Prime Minister José Luis Rodriguez Zapatero, congratulating Morales on his election and saying things like, "I imagine the only one not to have called you was George Bush. I've been here two years and he still hasn't called me". The Bolivian government protested to Spain, and the real Zapatero called Morales and apologized. The Spanish government in turn summoned the papal nuncio in protest.
Moreover, to make a prank call that falls afoul of the Telecommunications Act, 47 U.S.C. § 223(a)(1), the call must be done with the intent to "annoy, amuse, titillate, arouse, abuse, threaten, or harass".
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