But precious resources would be freed that could be spent elsewhere, for instance in cracking down on the use of multiple identities to commit welfare and credit-card fraud.

ECONOMIST: Counter-terrorism

But they're of little use in sifting multiple databases--what if the customer has a second card with a different company?

FORBES: Cyber-Sleuths

One allows users to tie multiple accounts to one card, and lets buyers choose the account they want to use with the push of a button.

FORBES: Credit Cards Reimagined