LONDON - British police said Friday they have arrested 12 men over a “sophisticated” plot to remotely take control of a computer at a branch of Santander bank and steal millions of pounds. Police found a device fitted to a computer in a branch of the bank in London which would have enabled the suspects to download data from the desktop machine. Police arrested 12 men, aged between 23 and 50, in London on suspicion of conspiracy to steal. The “very significant” plot targeted a bank branch in Surrey Quays in the Canary Wharf financial district, police said.