Have you scrubbed the hard drives?
From the BBC Website:
"UK bank details sold in Nigeria
Bank account details belonging to thousands of Britons are being sold in West Africa for less than £20 each, the BBC's Real Story programme has found.
It discovered that fraudsters in Nigeria were able to find internet banking data stored on recycled PCs sent from the UK to Africa...........
Real Story's investigation into the risk of identity theft from old PCs will the broadcast on BBC 1 at 19:30 on Monday, 14 August."
Full story here
http://news.bbc.co.uk/1/hi/business/4790293.stm