Criminal groups are characterised by various elements, as hierarchy, connection with a defined territory, permanence; but all their characteristics are devoted, at the end, to maintain the existence of the group, and to grant financial advantages to its members. To obtain the maximum of the economical profit, these groups are not devoted to a single, typical kind of traffic, but are involved in very different kind of criminal activities: cigarettes trafficking, prostitution, smuggling of migrants, and so on. We can trace many reasons owing to, at the date, is really difficult to fight and defeat organised crime; but the concrete threats that these organised criminal groups are carrying against legal economies, and the dangerous effects that they demonstrated to have on legal finances, make more and more urgent a common strategy in trying to stop their illegal behaviours.