In many countries, access to the courts is the main recourse to human rights. If you believe yours are being impinged, then your human rights should mean you can bring a complaint before the courts. These rules are often enshrined in a country's constitution. At the international level, then it is still the United Nations which is there to protect people and groups from abuses, although it does not always succeed. Organisations like Amnesty International exist to assist people suffering such violations and to monitor the activities of regimes which do not have sufficient safeguards in place.