Visualizing the LIBOR Bank Theft
Over the critical period of 2007-08, Barclay's LIBOR numbers were widely different from the actual figures, allowing them to manipulate the LIBOR rate and make bets on that change.
For a good summary of the LIBOR scandal, on-going fixes etc. Matt Taibbi's Rolling Stone articles are a pungent, if depressing read
This is a multi-trillion dollar market so even small manipulations can make big money. Conservative estimates put losses to us all in the tens of billions. As usual, no bankers went to prison and business continues pretty much as usual...