The data breach that occurred when HM Revenue and Customs lost two computer discs containing the details of 25 million people could have massive financial costs,according to a report from security company Gartner. Although there’s been no evidence to date that the discs were stolen when sent through internalmail, Gartner VP and distinguished analyst Avivah Litan warned that, “The type of data lost could be enormously valuable to identity thieves and other criminals, who could, for example,use stolen account numbers to take over bank accounts. This is why bank account numbers typically sell on the U.S. black market for as much as $400, compared with $5 or less for credit cardnumbers.” British banks might have to take emergency measures to monitor all transactions on affected accounts. In the worst-case scenario – proof that the data had fallen intocriminal hands – banks might have to close and re-open millions of accounts, which would include changing direct debit payments and issuing new cards, at a potential total cost of $500 million. However, Litan warned that the chance of identity theft was actually small, at just 1%. Meanwhile, e-mails have revealed that an official at the Revenue rejected a request from theAudit Office, which had requested the data in question, to filter some of it – namely address, bank and parent details – on the grounds of cost. A similar request to send the data assafely as possible was also apparently ignored. The political firestorm continues.