Shortly after Andrew Cuomo took office as New York attorney-general in January, his staff began briefing him on the hundreds of investigations still open when Eliot Spitzer left to become governor. One quickly caught Mr Cuomo's eye: a probe into whether college financial aid officers were conspiring with student loan providers to steer young borrowers to particular firms.

Mr Cuomo jumped on the issue because it dovetailed with what he says is his sense of what the attorney-general's office ought to do. Two-thirds of all US college students graduate with loan debt; if the allegations were true, many were paying higher-than-necessary interest rates because they had used the "preferred lenders" recommended by their universities.