Since these infrastructures transcend geographic boundaries, organized crime is internal in scope and thrives on national differences among the justice and law enforcement systems of sovereign States. Profit oriented, operating downward through hierarchical networks, crime rings resemble the organizational structures and management practices of the legitimate business world. Extensive criminal subcultures, such as South Italy's Cosa Nostra, have evolved over centuries in countries with extreme social polarities between wealth and poverty, but have not as yet emerged in Germany. For the time being, Germany is prey to operations being run from abroad and deploying local criminal elements only at the lowest, most visible levels of illicit activity. To combat the phenomenon, such law enforcement strategies as wiretapping; postal, telegraph, and transportation checks; and border controls must be implemented fully. Policies enabling greater protection for undercover agents and criminal informants must be adopted. The spread of organized crime in Germany can be anticipated due to continuing strains upon the economy (particularly unemployment) and to the inability to assimilate the large numbers of migrants from foreign countries with established crime rings.