This is a hugely powerful movie, and could make for a hard watch for some people. Why I enjoyed it - and why I think it is an important book, turned into an important film - is that it highlights a reality of the Camorra that they probably would rather wasn't made public; in the sense that it is not the glamorous life of Al Pacino in the second half of Scarface; its more akin to throwing someone in the canal in Eastenders after shooting them in the back. Lots of big fat men, eating lots of pasta, playing cards with the TV on in the background, wearing wife-beaters are the main protagonists in this world. Occasionally, trying to exert their authority, they get up from their cards and pasta and go out and sweatily murder some kids who have aspirations of being one of the next bosses - a medium sized fish in a massive pond.
The film paints a picture of the Camorra's flat structure (as opposed to the Mafia's hierarchy) with the factions in a state of constant flux and in-fighting. The overall message you are left with is one of small-timers living in squalid conditions and an overriding sense of futility and fragility.
I can easily understand why the Camorra are so cross about this film and the book, as it is, as a policeman from Naples said on Radio 4, one of the most powerful ways of breaking their control, by showing the image they would like to present themselves as (Goodfellas, Sopranos, etc) is a far cry from the reality. The person I watched this didn't enjoy it so much, probably because of the nihilistic message. Sugar-coated this film is not. The author deserves the full extent of government protection.