Bah ! That answer really does hack me off !!
However, dzug is absolutely correct that in order to prevent money laundering banks are required to demonstrate a 'trail' of the money - from a legitimate source into your 'current account' and then out again. The bank you hold your 'current account' will also be keeping an eye out as to from where the money is coming in the first place..........
As you are a fine upstanding citizen with nothing to hide, you doubtless will have nothing to fear..........apart from a further erosion of civil liberties with another strata of faceless pen-pushers having access to your private details.