Italian anti-mafia prosecutors said they seized a record $6 trillion of allegedly fake U.S. Treasury bonds, equivalent to almost half of the U.S.’s public debt.  The bonds were found hidden in makeshift compartments of 3 safety deposit boxes in Zurich.  Eight people were arrested in connection with the probe, dubbed “Operation Vulcanica.” The U.S. embassy in Rome issued a statement saying that they had examined the securities dated 1934, which had a nominal value of $1 billion apiece, although embassy officials didn’t have an immediate comment. The financial fraud uncovered by the Italian prosecutors in Potenza, where the bonds were stashed, includes 2 checks issued through HSBC Holdings Plc in London for £205,000 - about $325,000.  The checks weren’t backed by available funds, the prosecutors said. As part of the probe, fake bonds for $2 billion also were seized in Rome.  An HSBC spokesperson in London declined to comment when contacted by telephone. The individuals involved in the caper reportedly had been planning to buy plutonium from Nigerian sources - according to phone conversations monitored by the police.  The fraud posed “severe threats” to international financial stability, the prosecutors said in the statement. Swiss authorities also had a part in the investigation, until 7/22/11.  The Zurich public  prosecutor’s office provided material to their Italian counterparts in Potenza in 2011.  According to Italian authorities, their investigation initially focused on a Sicilian who was living in Potenza and was “already known for money laundering and exporting currency abroad.” Phony U.S. securities have been seized in Italy before and there were at least 3 cases in 2009.  Italian police seized phony U.S. T-bonds with a face value of $116 billion in August 2009 and $134 billion of similar securities in June of that year.  The U.S. Secret Service averages about 100 cases a year related to bonds and other fictitious instruments. For further details, go to: [Bloomberg, 2/17/12].