Perhaps more than most corporations, Citigroup knows the perils of moving personal data.
In February last year, a magnetic tape with information on about 120,000 Japanese customers of its Citibank division disappeared while being shipped by truck from a data management center in Singapore. The tape held names, addresses, account numbers and balances. It has never turned up.
And this week the company revealed that it had happened again - this time the loss of an entire box of tapes in the care of the United Parcel Service, with personal information on nearly four million American customers.
The problem of data security goes well beyond couriers and data tapes. And improving things takes time and money.
When so much commerce is conducted online and when just a few bits of stolen data - a Social Security number, a name, an address, a date of birth - can be turned into cash by opening false credit accounts, thieves have proved themselves skilled at getting the information they need.
ChoicePoint, a commercial data broker, was duped by con artists posing as legitimate businesses, allowing them to download sensitive information on thousands of consumers. And a thriving trade in credit card and bank account numbers continues to unfold on underground Web sites and Internet chat rooms.
Combating the crooks requires a holistic approach to data security, said Mike Gibbons, a security consultant for the global technology services company Unisys, and the former chief of cybercrime investigations for the F.B.I. That includes creating more secure online access methods, robust customer authentication, hiring dedicated data security staff, and improving the way large amounts of consumer data are stored or moved.
"All of these things have cost impacts," Mr. Gibbons said. "Businesses have to pony up the capital to change the way they are storing and holding data."
Given that 10 million consumers are now falling victim to some form of identity theft each year, according to the Federal Trade Commission, the stakes are high.
"I think there are some people who dismiss this as a sky-is-falling problem," Mr. Gibbons said. "But the sky has already fallen and it's just a matter of when a piece hits you in the head."