Italian anti-mafia prosecutors said they seized a record $6 trillion of allegedly fake U.S. Treasury bonds, an amount that’s almost half of the U.S.’s public debt. The bonds were found hidden in makeshift compartments of three safety deposit boxes in Zurich, the prosecutors from the southern city of Potenza said in an e-mailed statement. The Italian authorities arrested eight people in connection with the probe, dubbed “Operation Vulcanica,” the prosecutors said. Creating fake Treasuries is a “common scam, especially in Italy,” said U.S. Secret Service spokesman Edwin Donovan. The tipoff was the “astronomical” face value of each bond, he said. Fake bonds in high denominations are more common in Europe, where people are less familiar with the face value of U.S. Treasury bonds than in the U.S., he said.