Criminal accusations and the sentencing of citizens accused of incriminated conduct is a monopoly of the modern state. First of all this means that no individual citizen has the right to punish another individual. Secondly, every state determines the extent of its own jurisdiction, and determines what acts the state considers criminal. When a given act is punishable in more than one national jurisdiction, the courts of different states could judge the same individual concurrently or consecutively. However, European Union law limits repeated punishment for the same act in different states, the "ne bis in idem" principle prohibits double jeopardy. If needed the Court of Justice of the European Union interprets the notion of "same act", and will do this if requested by a national court in the course of any criminal proceedings. Violation of the ne bis in idem principle also constitutes a cause for bringing a case to ECHR.