Amnesty International monitored the proceedings against 12 Catalan leaders in relation to the events that took place in Catalonia in the fall of 2017 around the referendum on 1 October. After monitoring the trial and thoroughly reviewing the judgment, Amnesty International expresses its concern about the definition of the crime of sedition in Spanish law and the interpretation of the same by the Supreme Court. Amnesty International believes that this interpretation contravenes the principle of legality and permits the imposition of disproportionate restrictions on conduct that—though perhaps would involve breaking a law—would still be protected under the rights to freedom of expression and peaceful assembly.