The Electronic Privacy Information Center (EPIC), based in Washington, D.C., filed a third-party intervention with the European Court of Human Rights in a case about mass surveillance and transatlantic co-operation between intelligence agencies. The case against the United Kingdom involves a challenge brought by NGOs from all around the world. They argue that surveillance by British and U.S. intelligence agencies violates their privacy and freedom of expression rights. In support of the NGOs, EPIC provided the court with information concerning the scope of surveillance conducted by the NSA.