Several international film organizations and notable documentary filmmakers such as Laura Poitras, Liz Garbus, Alex Gibney, Errol Morris, and Roger Ross Williams supported the letter. Actors like Joaquin Phoenix, Penélope Cruz, Emma Thompson, Riz Ahmed, Olivia Colman, Richard Gere, Natasha Lyonne, Andrea Riseborough, Sandra Hüller, Javier Bardem, and Susan Sarandon signed it.