Cartels in the news

We talked about a few monopolies and cartels in class like OPEC and BG&E, but would you have expected a cartel in milk? They don't have a resource they control exclusively and they certainly weren't given control over something by the government. In fact, the government has fined them millions of Euros, as shown in the piece posted under Readings (on Blackboard). So how could they manage it? Hm. Sounds like an exam question.