In the next few months, hackers will try to penetrate the cyberdefenses of Britain's major banks and steal information about millions of customers. But for once they will be welcome.
Banks are on red alert after cybercriminals obtained details of 83 million clients from JPMorgan Chase this year, and Britain's leading lenders have signed up for tests that let teams of certified hackers attack at will.
The cyberwar games will mark a major escalation in how banks test defenses in a high-stakes battle with global criminals.