After subprime mortgages, shadow banking and robo-signing I shouldn't be surprised by another fraud that the banks have gotten themselves into. There's a good article in the economist describing what exactly Barclay's (and inevitably others) are guilty of:
LIBOR (london inter-bank offered rate) is everywhere, anyone who borrows or saves money is touched by it. The fact that these banks were brazen enough to manipulate this rate for their own profit is appalling. As the scandal spreads so will the outrage. In previous scandals the banks were generally ripping off "sophisticated investors" i.e. greedy people who should have known better. But scandal takes their fraud to a whole new level. Litigators must be thrilled about this - shit's about to get real.