For many years private security companies have been increasing. They are involved in various domestic sectors, but they are also more and more used in international interventions . Is the states’ monopoly on the legitimate use of violence put into question by the proliferation of private security contractors? In PRIF-Report No. 88 Private Security Companies and the State Monopoly on Violence. A Case of Norm Change?Elke Krahmann observes a transformation of the normative foundations and practices in the provision of security and demands a public debate on the political desirability and legitimacy of the private use of armed force.