Joint Study on Global Practices in Relation to Secret Detention in the Context of Countering Terrorism of the Special Rapporteur on the Promotion and Protection of Human Rights and Fundamental Freedoms While Countering Terrorism, Martin Scheinin, the Special Rapporteur on Torture and Other Cruel, Inhuman, Or Degrading Treatment Or Punishment, Manfred Nowak, the Working Group on Arbitrary Detention Represented by Its Vice-Chair, Shaheen Sardar Ali, and the Working Group on Enforced Or Involuntary Disappearances Represented by Its Chair, Jeremy Sarkin