I know trailer parks sound ridiculous, yeah. But Dutch trailer parks have long been a breeding ground for organized crime. 'Kampers' ( as they call the Dutch people living in these parks) are really a serious bunch, as funny as it sounds. The clan Van Wesenbeeck for instance belong to the top of European's crime barons.
The same can be said for the French gypsy camps. French Gypsies like the Hornec brothers are infamous names in European organized crime. Last year you had the Bengler brothers from Marseille doing some major and crazy stuff, mostly involving Kalashnikovs. They were Manush ( French Sinti gypsies).