This happened last year and is not about books per se - the rules changed about what could be sent in from home to prison, the idea being (as far as I can tell) that all prisoners are more equal unless they're prepared to work for prison wages to buy these things. The "scandal" at the time was about female prisoners not being able to be sent in clean underwear - they were running out less than a month into the programme according to the quotes given to the independent at the time by the same person quoted in your article above:
― Ian Glasper's trapped in a scone (aldo), Sunday, 23 March 2014 19:36 (eleven years ago)