The lessons of Equihack

EQUIFAX, like all credit-monitoring firms, trades on its ability to handle sensitive financial information. So there was grim irony in the news that the firm has been the victim of a particularly big and damaging data breach. The company reckons that more than 143m people, mostly Americans, have been affected. The pilfered data include addresses, credit-card details and Social Security numbers. The Social Security numbers are especially valuable: they are the closest thing America has to a centralised national-identity system, and are far harder to change than a password on a compromised account.