A great number of institutional investment vehicles, including here in America, have their bond rates pegged to the Libor rate, as do mortgage rates, credit cards, and other loan rates. Many governments and municipalities have their debt rates set to float along with Libor, so if that rate changes, the amount that needs to be paid back on their bond offerings will often go up. The cost of manipulating Libor by just a few basis points can run into the millions of dollars for a debt offering - and may have put trillions into the banks' own coffers.