BBC2 Sky Atlantic If you’re after an exciting, twisty programme about police corruption that doesn’t also feel a bit like sitting an exam in Line of Duty studies, then Bent Coppers: Crossing the Line of Dutycould well hit the spot. As both the timing and subtitle not so much suggest as bellow, this three-part documentary series is an obvious attempt to cash in on its fictional counterpart. Happily, though, it’s a successful one. In Wednesday’s second episode the focus was on 1970s Soho, where the most reliable way to make a fortune was by opening what the narrator Philip Glenister called, in suitably 1970s argot, ‘dirty bookshops’. Of course, there were certain overheads involved, like rent and huge bribes to the police. But once they were sorted, the apparently fathomless human desire for pornography did the rest. Granted, the police would occasionally raid your shop for form’s sake. On the other hand, you could pick up the confiscated material a couple of days later from the local nick.