The rights of children form a subset of human rights, and their purpose is to recognize the special needs of children in order to protect them as they mature and grow up. The constitutional rights of children are exercised and protected by law to the extent established by the Constitution and adopted by international instruments. The European Court of Human Rights has been established to ensure compliance with the commitments undertaken by the High Contracting Parties to the European Convention on Human Rights and the Additional Protocols, and acts as a permanent tribunal and as a convention supervisory body. Children's rights have often been called into question in the case law of the European Court of Human Rights and the European Committee of Social Rights, and in recent times the Court has identified a number of violations of the European Convention on Human Rights. The jurisdiction of the European Court of Human Rights extends to all matters relating to the interpretation and application of the Convention for the Protection of Human Rights and Fundamental Freedoms and its Protocols, and unlike the Court of Justice of the European Union, the European Court of Human Rights has broad jurisdiction over children's rights. In criminal proceedings, children have the right to a fair treatment and access that is tailored to children, and judicial proceedings need to be tailored to their needs to ensure their effective participation.