Police will seek special powers to investigate tens of telephone calls they received from a prankster in the last few days forcing them to chase down more than 30 bomb hoaxes across the city. Police say that an unidentified man, about 35 years old, is suspected of making all the bomb hoaxes on high-profile targets, but they cannot trace the calls as the data is protected by privacy laws. A source said that police will request access to this information from judicial authorities on the grounds that he is a threat to the city. After receiving calls for some 22 bomb hoaxes up until Wednesday night, nine more calls were made by noon yesterday. Among the targets was the office of Prime Minister Costas Karamanlis, the Defense Ministry and the city center, which was full of holiday shoppers.