Let's ask a Lloyds Banking Group employee.
Britain’s largest mortgage lender today agreed to pay 226 million pounds ($383 million) in fines to U.S. and U.K. authorities for manipulating benchmark interest rates. Lloyds employees sought to manipulate the London interbank offered rate, benchmark for more than $300 trillion of securities worldwide, to profit from derivatives and to make the bank seem financially healthier than it was, according to regulators...When a Yen Libor submitter at Rabobank told a Lloyds counterpart he was entering an “obscenely high” rate on July 28, 2006, the British bank’s employee responded by saying “oh dear..my poor customers....hehehe!!”
There you have it.